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OCTOBER 1920. Vol. XLV. NO. 688. THE ANALYST. PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS AND OTHER ANALYTICAL CHEMISTS. A STUDY OF THE DE3’ERMINATION OF POTASSIUM AS TEE PERCHLORATE AND THE SEPARATION FROM SODIUM BTC. BY 33 LEITCH MOBBIS F.I.C. ( B d at tlae MW- J u ~ 9,1990.) THE work outlined below is a summary of neerly six yeairs’ experienoe of the per-chlorate prooees find it is oleimed that given attention to easential deteils the results approaoh to soientifio aooursoy. In the oourse of thie work the strength of aIoohol is expressed as pementage by volume 8‘ P d o r i o aoid ” means the aqueous wid end in the experimental work a 20 per cent. solution wea ueed. The formula HCIO refers to the absolute mid. The insolubility of poteesium perohlorate in strong aloohol wes observed by &rnlla,s (Am.C h k Phya. 1831,46,294) who desoribed en analytioel proems based on this faot. Sohloedng (Ompt. r e d 1871,73,1269) seems to have been the first to publish tirial results by the method. He emporated the qolution with parohlorio acid nedy to dryness in a send-bath treated the oold residue with small quantities af strong aloohol and deomted. “The more soda present the mom sodim perahlorate is retained by the perchlorate of pokssium; th#~6ffore P’t b b e t to &soh the p t & wmited pmhbvats of potcce8izcnc in tha hf pdsible mmmt of hot water and evaporate to drynese. Two more waehings with dcrohol complete the washing.” Besalts &hen on a mixture of NaCl+ KCl are remarkably close to the truth. No determination on a pure potassium salt alone was made.The aoouraoy of these results may be esoribed partly to the use of nearly the minimum amount of doohol (90 to 40 0.0. in all) and pertly to the feat thet the preaanoe of rrodinm per-ahlorate oonsiderably reduoes the slight solubility of the potassium perahlorate in dmhol; in addition the potassium perohloretie retains alight treoes of the sodim salt even after the perohlorate reeidm remaining after the prelimiSa,ry washing wi& &oh01 is rediieeolved and the solution is again evaporated to dryness 850 MORRIS A BTUDY OF THE DETERMINATION OF POTA-SBIUM Wense (ZeiMz. artgew. Chm. 1891 4 691; 1892 5 233) used 96 per oent, alcohol oontaining 0 2 per cent. by weight of HClO as the wash liquid which oon-eiderably reduces the solubility of potassium perohlorate.The perohlorate residue was extraoted twice with 10 C.C. of this mixture and then collected and washed with the stbme liquid. Then finaily it was washed with a few 0.6. of pure alcohol to free it from traces of adhering perohloric acid. Tared filter papers were used. Drying temperature 120’ to 1300 C. 6’ The whole process requires 50 to 7.5 grms. of alcohol.” Caspari (Zsitsch. angew. Cham. 1893 6 68) applied the process to the direot estimation of potash in fertilisers ashes etc. containing Fe Mn Al PaO and alkaline earths. He recommended (a) Filter tubes with mbestos ; (b) wash liquid oontaining 97 per cent. alcohol and 0-2 per cent. HC10 ; (c) two evaporations with perchloric acid finally to a syrup before treating with wash liquid; (d) extraotion of cooled residue with 20 C.C.washing fluid decanting and repeating extraction with 20 0.0. more; ( e ) dissolving residue in hot water snd re-evaporating a8 suggested by Sohloessing ; (f) transferring with the washing fluid and finally washing with a few C.C. of pure alcohol. These recommendation8 are improvements excepting the use of 20 C.C. of wasb liquid instead of the 10 C.C. recommended by Wense for each of the two preliminary extractions. The usual desoriptions of the perchlorate process follow Caspari a s regards the amount of wash liquid for extraction but ignore nearly all the other details emphasised by him. D. A. Kreider (Amer. J. of Scieme 1895 a 433 ; reprinted Ohm. News 1896, 75 9-17) followed Caspari’s details using pure potassium ohloride (0.1 grm.) and also a mixture containing a known amount of potassium chloride.A Oooch crucible is recommended. The results were good. In the case of the pure salt the error waa W. A. Davis (J. A g k . Sciertce 1912,5 58) made a d ~ t d e d study Q€ the proem. He evaporated the solution onoe on a sand-bath with perchloric acid until it fumed strongly. The perchlorate residue was treated with 95 per cent. alcohol and after decantation transferred and washed with alcohol to which 0.2 per cent- HClO, had been added and finally washed with about 5 C.C. of pure 95 per cent. ahohol and dried at 100° C. The results are fair but show somewhat wide variations. At the close of the paper he reoommends that after preliminary extraction with the 20 O.C.doohol the rest of the washing should be carried out with a dution 0% potassium perchlorate in 95 per oent. alcohol saturated at room temprfbtnre, Thin and Cumming (J. Chem. Soc. 1915,107,361) recommend the use of the saturated 801UtiOn of potassium perchlorate in 96 per cent. alcohol for the washing liquid as suggested by Davis. Beyond stating that the results are aocurate they give no analytical data. Their paper is chiefly useful for their solubility determina-tions of potassium perchlorate in aloohol of various strengths and in alcohol containing varying amounts of perohlorio acid, Baxter and Kobayashi (J. A ~ w . C h . Soc. 1917 39 249) have shown that absolute alcohol containing 0.1 per cent. HClO ditmolves at Oo’ C. aa little potassium perchlorate as any ymticable mixture (1.9 mgrm.per 100 c.c.) although the salt is still appreciably soluble even in this liquid. They recommend washing at a Drying temperature 1800 to 150’ C. to 2v mgrm. below truth. Total filtrate dose to 50 C.C AS THE PERCELLORATE AND TKE SEPARATION FROM SODIUM ETC. 351 temperature near 0" C. with & saturated (at Oo C.) solution of potassium perchlorate in the above liquid They used a platinum sponge crucible and dried at 200° C. in an eleotric oven. The results were good but working at 0" C. i s obviously in-eonvenien t. In a later p;&per (J. Amer Chem. SOC. 1920,42,735) they agree with the criticism of Gooch and Blake (see next paragraph) that potaseium perchlorate may be precipitated from this washing solution when much sodium is present.They modify the process by making a preliminary extraction with 20 C.C. of absolute alcohol con-taining 0.1 per cent. HC104 but no perchlorate and then waahing with the per-chlorate solution (saturated at 0" C.,) already described. Otherwise the process in detail is the same. A series of good results is quoted. In the presence of much sodium re-solution of the precipitate in water and re-evaporation at least once is necessary. Gooch and Blake (Amer. J. Sc&nce 1917 44,381) have shown that at ordinary temperatures the addition of a wash solntion saturated with potassium perchlorate, to the perohlorate residue leads to precipitation of some of the dissolved potassium perchlorate when much sodium perchlorate is present. (Cf. Baxter and Kobrayashi,) They recommend the um of 97 per cent.alcohol containing 0.1 per cent. HCIO as wash liquid throughout the process and avoid loss through ~01ubilit.y of the KC10, by restricting the amount of wash liquid used. They treat the perchlorate residue first with 10 O.C. only of washing fluid; decant; redissolve the residue and again evaporate when much sodium is present; treat again with 10 c.o. decant and finally wash with 5 0.0. of the same wash liquid added in portions. In dl their determinations the total filtrate was kept at 25 C.C. Repeated evaporation with pemhlorio acid is desirable if more than 0.2 grm. of NaCl+ KCI is preeent. (It will; be seen that the final washing with pure alcohol usually prescribed is dismrded; this washing with pure alcohol is the chief cause of the low results generally found in the perchlorate method.) The drying temperature is 130' C.If these details are followed the problem of getting oonsistently accurate results by the perchlorate procees is solved without the use of a saturated perohlorate solution for the washing. The process I have adopted since 1914 is the same in nearly %very detail as Goooh and Blake's. The perohlorate process has also been applied by some workers to the precipitate of potassium-sodium-oobaltinitrite. This is a useful process when sulphates or tartaxic and oitric acids are present. Bennett (ANA~~YST 1916,41,165) used #. The results axe good ; generally a little higher than truth. Notes ON the Vaqing Procedures ghen aboue.-Wense's suggestion of using 10 C.C. only of the wash liquid for eaoh washing by decantation has been neglected.I had adopted it before I saw Goooh and Blake's phper. Most text-books follow Csspari's quantities of 20 C.C. eaoh time. This increased amount is probably of little moment in the case for which Csspari describe8 the method-viz. the direct deter-mination of potash in mixed 'fertilisers etc. where considerable amounts of other bases and also phosphoric acid may be present ; but when only a pure potsssium salt is present low results will be obtained. The final waehing with pure alcohol to remove traces of perohloric acid is unnecessary when asbestos filters are used an 352 M O B I B A STUDY OF THE DETERMINATION OF POTA8SIUM the precipitate dried at 130” 0. or higher. Davis dried at 100” C. ; a higher tem-perature is better.The wash liquid should contain at least 97 per oent. aloohol after the addition of the perchloric aoid and there is no objection to using absolute alcohol containing perohloric aoid. With lower aloohol strengths than ‘97 per mnt. the solubility of the potassium perchlorate increases considerably. Two evaporations with perchloric acid should be made; if an excess of per-ohloric is present at the end of the first evaporation the second evaporation will suffice in all ewes. The Qooch cruoible is the best filter. At least one solution of the precipitate followed by re-evaporation is necessary after preliminary extraction with wash liquid when sodium or other bases are present ; otherwise the results may be above the truth. Finally it is advisabIe to keep the total amount of wash liquid as low as possible as too free use of it will make the results low.Ia$wme of other Substames present Ammonium Salts must bs absent.-The results obtained by Sohloessing show that the presence of alkaline earths and magnesia exerts but little effeot on the results and Caspari has shown that it is not hecessary to remove phosphoric aoid and that it is only necmm,ry to remove sulphuric acid. This last is absolutely essential owing to the insolubility of soditim snlphate in aloohol. In his paper Davis shows that fair results are obtained on pure potassium sulphate without removing the sulphuric acid and states that it is not always necessary to remove sulphuric acid; but he seems completely to have overlooked the point that the removal of Etnlphurio aoid is necessitated in general analysis by the insolubility of sodium sulphate in alcohol md he himself found tha,t when magnesium was present &S sulphate the removal of the snlphuric acid was neoebsary.In a later paper (J. Chem. SOC. 1915,107,1680) he reoomrnended the remov&l of sulphuric aoid in a11 cases exoept in the analysis of pure pofiaesinm sdphate. It is evident that Davis assumed that sodium sulphate on evaporation with perchloric acid behaves similarly to potassium sulphate. This is not the case ; &e perchloric acid treatment leaves sodium sulphate unchanged. This is a v e q important point to note and is referred to below under As regards magnesium Kreider treated Ob15 grm. magnesium carbonate with excess of perchlorio acid evaporated the solution and treated the cold residue with alcohol when Pra,cticdly all perchlorates seem to be freely soluble in strong alcohol except those of potassium rubidium cwmium and ammonium.Ammonium perchlorate is slightly soluble in alcohol-about 2 per cent. In using the perohloric proceBs it is essential to use sufficient perchloric acid to oonvert completely all the baees present into perchlorates owing to the insolubility of most chlorides etc. in aloohol. &eider found that to secure a nearly complete separation of phosphoric acid from .the potassium a aonsiderable excess of the perchloric acid should be left upon the potassium perchlorate before it is treated with aloohol. Testbook Deswiptiorts of the Process.-These in geneml are faulty.Mellor‘s 1; Treatise ” follows Caspari generally but omits the re-dissolving and re-evaporation of the residue after the fireb treatment with the alcoholio fluid. The final washing lwith pure alcohol is omitted; this is an improvement. Experimental.” perfectly clear solution was obtained &3 THE PERCELORA'I'E AND THE SEPARATION FROM BODIUM ETC. 353 Treadwell (@ant A d IZ.? English edition) describes the procese amurately in Caapari's own words but makes a serious errqr at the end by sflying that finally, the precipitate is to be mashed with 50 to 75 O.C. of pure alcohol. If this is done, the results must be low unless in the cam where a very large amount of sodium ie present. This error has arisen through misreading Wen-se'Ei word@ '' the whole procees requiring 50 to '75 grms.of alcoho1," this implying a total filtrate of 60 to 80 C.C. There s,eerns little doubt that this description may have led to the con-demnation of the process by some workers who have tried it on a pure potassium sat following Treadwell's directions and found the results too low. The Stassfurt modification of the perohlorate process for crude potassium salts is desoribed by Lunge and Keane (Tech. Methods of C h . Aml. Vol. I. Part II., p. 530). The details resemble those of Caspari but the re-dissolving of the per-ohlorate is negleoted. The washing solution is 96 per cent. alcohol to which 2 per cent. (of 20 per cent.) perchloric acid has been added. Finally the.perchloric acid is removed by washing with a minimum of pure 96 per cent.alcohol. A water-bath is specified for the evaporation ; this is unsatisfactory a higher temperature (120" to 130" C.) is necessary for the final stage of the evaporation since the perchloria aoid does not reach the fuming-point at the temperature of the water-bath. The washing solution it will be noted contains only 94 per oent. alcohol and 0-4 per cent. HClO,; 0-2 per cent. HClO is suEoient ; the extra amount of aoid reduces the alcohol content by a,n extra I per cent. Pmchkic Acid-Pure perchlorio acid ( 6 reagent," has only been obtainable commercially in the last fifteen gears. Kreider described a very convenient method of preparing the acid from pure sodium perchlorate by treating it with fuming hydro-chloric acid (sp. gr. 1*2) filtering off the sodium chloride precipitated on asbestos and concentrating the filtrate to the fnming-point.Such an acid contains about 40 to 50 mgrms. of sodium perchlorate in 1 c.c. and is of 60 per cent. by weight (equal to nearly 1 grm. HC10 per c.c.). Thin and Cumrning found that Merck's '' pure " perchloric acid (20 per cent.) gave 0.1476 grm. solid residue from 10 C.C. and contained some potassium perchlorate. Another lot of acid gave 0.049 grm. from 10 O.C. Perchlorio acid of reagent purity has been obtainabla both from a German and at least one English souroe since 1910 such mid leaving only traces of visible matter on evaporation of 10 O.C. and giving no result fur a blank when put through the andytical process for potash. STRENGTHS AND SPECIFIC GRAVITIES OF PERCHLORIG ACID SOLUTIONS..-I I I Specific Gravity. Boiling-Point. 1.782 at 15.5' Rosooe) "1.82 [Boscoe] 1-12 100 71.6 90 110' (Roscoe) 203' (R06000) 120 --* Aqueous acid of constant boilingpoint approximating to the pornposition of the dihydrah HClOd 2H20 AS TELE PERCHLORATE AND TEE SEPARATION FROM SODIUM ETC. 355 The 98 per cent. alcohol can be easily made by mixing 110 C.C. of absolute aloohol (of not less than 99.5 per oent.) with 100 0.c. of 96 per cent. aloohol. Proeess.-In nearly all cases the solution of the salt was evaporated with perchloric aoid three times in all and in the final evaporation taken practicrally to dryness. The residue (in the analyses following after No. 3 and No. 3e. of Z'ables I. and 11.) wag treated with 10 0.c. of wash liquid stirred well with a flat-headed glass rod sllowed to stand ten to fifteen minutes when soaiam was present, ocoasionally stirring ; the solution allowed to settle and the liquid decanted through a weighed Gooch crucible containing asbestos.When only potassium was present, the precipitate was then rinsed out direotly with the wash liquid in measured quantity by means of a wash-bottle. When sodium was present the basin containing the residue from the first deoantation was placed on the top of the air-oven for a few minutes till the aloohol was evaporated; then the residue was dissolved in the minimum amount of boiling water and again evaporated to dryness. The treatment with 10 0.0. of wash liquid and deoantation was repeated and the residue then transferred oompletely by using the latter 10 O.C.of the filtrate. Finally a measured volume of wash liquid was added (by the use of a small pipette) in portions to oomplete the washing on the filter. The Gooch orucible and contents were then dried for about an hour at 130' to 150' C. cooled for one hour in a deaicoator and weighed. After weighing 2 to 3 C.C. more wash liquid were passed through the filter, and the drying and weighing repeated. The weight was taken as constant when on washing with 2 to 3 C.C. of liquid the difference on successive weighings did not vrwey by more than one or two tenths of a milligram. in all oases the weighings were made by the method of vibrations; pipettes and weights were calibrated and the solutione used were adjusted at 15" C. and measured off after being always brought to the same temperature.The usual variatione obtained in weighing crucibles etc. which may easily amount to 0-0003 grm. or more, due to absorption of air and moisture by the glaze of the crucible during weighing, were thus minimieed by weighing quickly. On the average the weighings may be taken as correct within k 0.0001 grm. Apparatw &.-In nearly all cases porceltlin Goooh crucibles of 10 C.C. capacity were used ; in one or two instances only a 20 C.C. quartz " Gooch " was employed. For amounts of potassium perchlorate from 0.4 grm upwards the 10 C.C. Goooh " ia rather smalL The same &sbe8to6 felt was used over and over again the cruoible, after finishing an anelpis being washed out repeatedly with boiling acidulated water.After six or eight estimations the interior of the crucible will be found to be slightly stained yellowi& brown and the weight of the empty crucible will show an increase of 0-1 to 0-2 mgrm. even though the acid gives no weighable residue in the blank prooess. This oolour is apparently due to the action of perohloric acid on the alcohol or on the impurities (tie. the traoes of aldehydes or esters) contained in the alcohol. In practice it is well to ignite the empty cruoible containing the a8b~8f06 after six determinations have been oarried out; then to pass gome distilled water through the orucible and dry at 130° to 150" 0. &(J u~ual. It is essential to have proper facilities for drawing off the filtrate conveniently. The usual pressure-flask is quite inoonvenient.Filtering direot into a beaker o 356 XORRIS A STUDY OF THE DETERMINATION OP FOTASSIUM flask inside an exhausted bell-jar is satisfactory but the handiest apparatus is the Gooch filter-tube No. 1180 in Townson and Mercer’s list. T’his is a wide-mouthea oylindrical separating funnel with stop-cock at -bottom and a sidg tube to connecb with the pump. The Wash-ButtZe.-It is best to use a wide test-tube for this as the small amounb. of wash liquid used makes even a small flask unsuitable. The outlet tube and jet should be made from one piece of glass tubing 8s contact with rubber connections is best avoided. The portions of waeh liquid used should be approximately measured. It is best to use the wash-bottle in trainsferring the filtrate rinsing ouii directly into the 66 Gooch ” ; after nearly all the precipitate appears to be transferred, it is essential to rub round oarefully the sides of the dish by using the tip of a feather as a brush.It is very difficult to know when the dish has been properly cleaaed, the alcohol seems to reduce the visibility of the precipitate and the usual rubber-tipped rod is unsuitable for this transference as the rubber soon gets slightly sticky owing to the action of the tram of perchloric acid in the washing fluid. A white porcelain basin is useless. A blue glazed porcelain basin (Boyal Worcester ware) was used some cams; this is satisfactory for enabling one to judge when all the precipitate has been transferred. But Gooch and Blake have noticed that perchloric acid has a decided mtion on glass and the results in the Tables I.and 11. S88m to show a similar action in the ease of the blue glazed porceldn. In such cases the perchlorate of potagsium may contain silica. EvaporatioN.-A water-bath is Unsuitable since the perchloric aoid oannot be concentrated to the fuming-point below 120” C. Davis reaommendea a sand-bath, which is inconvenient in quantitative work. I t is best to use some form of hot air-bath. The simplest device is to use a shallow sctnd-bath tray covered with a set of rings on which the dish is Ref. The heat is applied by means of a bnrn8r with a rose top. ’With a little practice the temperature is easily adjusted to allow of speedy. evaporation without the liquor ever boiling even towaids the end. In all these test andyses the air-bath and the dish were plaoed under an inverted Victor Meyer funnel so as to exclude dust from the atmosphere.The following hints on preparing the asbestos felt in the tLGooch” may be useful Shake up a fair quantity of the prepared asbeehoe emulsion in water let the whole settle partially by leaving it to stand two or three minutes. Decant off the liquid containing the finer particles of asbestos into another bottle. Prepare the ‘‘ Gooch ’’ by running through some of the coarser emulsion till the perforations are evenly covered. Then add a few 0.0. of the finer emulsion to 611 up the larger interstice6 that may be left in the first layer of the felt. Then put in a perforsted plate and add a little more asbestos as before. Such a felt will retain bhe perchlorate in all ases even though the previous stirring may have reduced the precipitate to fine powder.With similar precautions an asbestos felt can be prepared to retain calcium oxelate and even barium sulphate and yet to filter quickly under a, medium pressure. With this devioe a very thin layer of asbestos suffices. It is sometimes advised to avoid breaking up the precipitate too much,in case it The tip of the jet should be drawn out very finely. Platinum or quartz dishes are preferable to glass 358 NO, 2k 3 A MORRIS A STUDY OF THE DETERMINATION OF POTABSIVM TABLE II.-POTASSIUM IN PRESENCE OF SODIUM. 0.1368 01368 01368 01368 03511 0.2083 0.0988 0*0988 0.0273 0.0973 0.02'73 0.0122 0.0122 0.0122 0.0123 000611 0.00305 0.4590 0.5096 0.13 0.20 0-2 0.2 0.3 0.5 0.2 0 2 0.2 0.2 0.2 0.5 0.3 0.3 0.2 0.12 0.13 0-5 0.5 0-5 --KC104 weighed (Grm.).02525 0.2547 06562 0.2547 0.6538 0-3877 Oa1838 0.1833 0.0512 0-0502 0.0505 0-0242 0.0236 0.0234 0.0221 0.0114 0*0056 0.8622 0.9618 0*0001 g! B p -13 13 5 5 10 10 20 21 10 10 10 15 15 15 15 15 15 15 15 15 --100 90 30 30 35 35 27 28 38 30 32 30 33 30 30 30 27 35 35 35 --a Z A &i a52 0.1359 0.1371 01379 0.1371 0.3518 0.2086 0.0989 0.0986 0.0276 0.0270 00278 0.0130 00127 0.0126 00119 OnO0613 0*00301 0.4639 0.5175 0.0000 Treatment of Perchlorate Reaidue.* 20c.o.+ 20 0.01 + wmh- t ings. Not redissolved 10 C.O. + 10 C.C. + wash-ings. Not redissolved Bediclsolved 9 9 ¶1 11 99 Not redissolved Redissolved Not redissolved Redissolved ts Y I #1 Not regssolved Not redissolved 9 s, Potash reooved. (per (lent.). 100.22 99.8 * 4a to 23 inclusive-10 o.c.+ 10 o.c.+ washings. t KCl weighed off separate1 $ Through not having a " &och cruoible prepared the perahlorate after treatment with 10 C.C. of wash li uid stood all night before filtration. Glass dish used for 2A and 3a. Green glazed dish for 5 ~ , Quartz%ieh for all othem. The term solved " means that the residue aft;er the first decantation was dissolved in hot water and again evaporated to dryness. 8 In Nos.22 and 23 the errors on KC1 are respectively +0*0049 and + 0.0079. This shows the necessity of redissolving the residue as desoribed in the case of muoh sodium being present. Baxter and Kobaysehi found a somewhat sidar error. Transferred by filtrate from second 10 0.0. In Table 111. the KClO was redissolved md the solution again evaporated (dter the fkst decantation) .f to 1 0.0. more perchloric being added. The precipitate was franrderred by the mmnd portion of the filtrate. A. Taken to drynees treated with 10 c,o. of washing fluid decanted. After the re-evaporation 10 0.0. of washing fluid again used and decanted. B. T&en to a moist pastiness 10 otc. of absolute alcohol added aind dwanted ; 10 C.C. again added to the paty residue on re-evaporation with addition of little perchloric acid and the deottntation repeated AS THE PERCHLORATE AND THE SEPABUATION FROM SODIUM ETC.359 KU1 taken Na2Hp04~12H20 (Grm.). (Gm*)’ C. Taken to dryness 0 2 O.C. perchloric acid added we11 stirred then 10 C.C. of D. Same as C exctept that I2 0.c. of &bsolute alcohol used eaoh time in plaoe of E. Same as C but using double the amount of perchloric acid 0.4 C.C. eaoh time. F. Same as B using 15 C.C. of 98 per cent. alcohol for each deoantation. 98 per cent. alcohol added and this treatment repeated. Results good. 98 per cent. Results too high. KC104 Weighed (Grni.) TABLE 111.-POTASSIUM IN PRESENCE OF SODIUM PHOSPHATE. -No. -1 2 3 4 5 6 7 8 9 10 11 l a I I-00988 0*0988 0*0988 0.0988 0.0988 0*0988 0.3447 0.3447 0.3447 0.3447 0.3447 0.3447 0-4 0.26 0.4 0.4 0.4 0.4 1 1 1 1 1 1 0.1878 0.1834 0.1842 0*1828 0.1838 0.1834 0.6613 0.6617 0-6436 0.6397 0.6420 0.6408 4a 5 gg ;- 3 15 20 20 18 16 16 15 15 13 13 12 10 Volume of Filtrak (C.C.) 35 29 40 30 26 30 45 45 46 46 45 49 KCl found (Grm.) 01010 0.0987 0*0991 0.0984 0.0989 0-0987 0-3558 0.3560 0.3463 0,3442 0.3455 0.3448 Error on CC1 (Gm) 4- 0~0022 - 0*0001 + O*OOO3 - 0*0004 + 0*0001 - 0*0001 + 0*0111 + 0.0113 + 0*0016 - 0*0005 + O*OOO8 + 0*0001 (see Bbove).A B B B C C D D E F F F recovered (per Uent.). I NOTES TO TABLE 111.-In presence of phosphoric acid it is evidently unsafe to evaporate the perchloric solution to complete dryness as the phosphoric acid if nearly completely dehydrated dissolves very slowly in the wash liquid and cannot be completely washed out of the preoipitate in such cases.(See No. 1 Table 111.) Kreider recommends in this case that a considerable excess of perchloric acid should be left in contact with the residue before treatment with alcohol. Caspari in describing his process for the case of fertilisers eta where phosphorio acid and alkaline earths are present evaporated the solution with perchloric acid to ( 6 syrupi-ness ” only and recommends the avoidance of evaporating off too much perchloric acid. This means that varying amounts of water (in the perchloric acid) will be left on the residue and hence on treatment with the washing fluid the alcoholic strength of the lather will be considerably reduced by an indefinite amount varying with the excess of perchloric acid left on the residue.For this reason the expedient was tried of taking the residue first to dryness, and then moistening it with 0.1 or 0.2 C.C. of perchloric acid and adding 10 0.0. of pure strong alcohol of 98 per cent. SO as to keep the alcoholic strength of the liquid in contact with the precipitate as near 97 per oent. as possible. (Procedure C.) Final washings were made with the usual mixture. This procedure gives good results (NOEI. 5 and 6 Table HI.) but when tried u 360 XORRIS A STUDY OF THE DETERXINATION OF POTAMIWM larger quantities of sodium phosphate the results were amsider&bly too high (see Nos.7 and 8 Table 111.). Prooess F however gives good results. It seems besf, then to evaporate to a moist pasty oondition when muoh phosphoric acid is present and to treat the reAidue with 15 to 20 o.o of 98 to 100 per cent. alcohol for erlkoh decantation. Finally to wash with the usual wash liquid. The free phosphoria aoid pressnt seems to have no effeot on the solubility of the potassium perchlorate in the washing fluid. 1. Taken 00988 grrn. KC1+0*07 grm. MgO . . Found 0*1050 grm. KC1, 2. ,# 0.0988 , KC1+@2 , MgO . . , 00990 ,) KCI. 3. -, 00988 , KC1+@2 , MgO . . , O*O99O , KCI. Deterrriiwtion in PT~S~TW of Magnesium : Filtrate in ewh case-32 C.C. First residue in each case redissolved after first deoantation with wash liquid.. The result of No. 1 is too high. On washing with 5 to 10 C.C. more wash liquid the loss was but slight and the perchlorate still showed the presence of magnesium. This is probably due to some over-heating in trying to carry the evaporation to dryness. When fumes of perchloric acid had nearly ceased coming off the residue was still pasty while hot and the temperature was carefully raised to get nearly complete dehydration. It is probable that magnesium perchlorate which seem8 to cryetsllise with a considerable amount of water of crystallisation partially decom-poses before campEete dehydration can be effected Rome magnesium oxide being formed. Magnesium chloride behaves in this manner and apparenbly the per-ahlorate af magnesium resembles the ohloride in fhie respect.On account of this behrtviour in Nos. 2 and 3 above the evaporation was stopped when the fumes of perch€oric acid were still just faintly visible. The pasty residue so obtained sets solid when removed from the heat and when cold forms a hard cement-like maw. It is best to add the 10 C.C. of wash liquid to this and to set aside for an hour or two before attempting to Break up the mass. Any premature attempt at stirring up the D&SE will inevitably lead to loss by splashing. It is evident from the note on Experiment 1 above that the washing must be oomplete since passing more wash-liquid through the Gooch after drying at 130" to MU0 C. will have but little effect in removing any magneeium left on the perchlarate as the magnesium will after the drying be partly preeent as magnesium oxide.Se.paratbn fim CaZcliwm.-Calcium evidently does not interfere with the process. In the evaporation the mass of perohlorates obtained (which is semi-fluid while hot dthough fumes of perchloric acid have almost oeased) sets to a hard mass and the disintegration of this by the wash liquid is best carried out as described under magnesium. Taken 0*0988 grm. KC1 e 0.07 grm. CaCO Found 0.0986 grm. KC1 Filtrate . . . , 0.0988 , KCl+0*14 , CaCO . , 0*0990 , KCJ30 0.0. In Presme of Calcium and Hagnesitm togethsr.-Taken 0.0988 grm. KCL + OO? In Preseme ofBuriwm.-Barium per se does not effect the results but the con-grm. CaCO + 0.07 grm. MgO. Found 0.0985 grm. KC1. Filtrate 30 C.C A8 THE PERCHLORATE AND THE BEPABATION ZROM SODIUM ETC.361 version into perchlorate must be complete since barium chloride is very insoluble in alcohol; still in praotice for accurate results it mBy bs advisable to remove the barium when considerable quantities are present unless the evaporation can be oarried out on some form of eIectrioally heated radiator ; otherwise the potassium perchlorate may contain appreciable amounts of barium sulphate owing to the gas. At a very early stage of these test analyses the influence of barium was investigated, but the experiment failed owing to this cause. After the first evaporation on adding water to redissolve the residue gave a cloudy solution which was due to the forma-fion of barium sulphate. In the results below the evaporation was carried out on the air-bath described, using a large asbestos card to deflect the products of the burnt gas away from the liquid.Even then traces of barium sulphate were present in the perchlorate weighed. 1. Taken 0.0122 grm. KC1+02 BaCI,2H20. Found at first 0-0126 grm. KCI. Corrected by deducting Baf30 present 0.0123 grm. KCl. 2. Taken 0.0062 grm. KCl+ 0.1 BaCl cryst. + 0.2 MgCl cryst. t0-05 CaCI, oryst. Bound 0.0057 grm. KC1. In this last case the filtrate was slightly opales-cent probably a trace of BaSO was present which passed through the asbestos. Detemninatwn of pwre Potassim Su@hate.-Davis found that the direct estima-tion of pure potassium sulphate wae possible and the following analyses were therefore fried. I t is obvious that on evaporating potassium sulphate solution with the perchlorio add free sulphuric acid is libemted and that the free sulphuric acid cannot be removed by evaporation without reversing the reaction.For this reason the evaporation was carried out at as low a temperature as would suffice to drive off the perchloric acid in fumes. This leaves the residue of perchlorate quite moist, since the free sulphuric acid at this temperature must still be in a fairly dilute condition. On now adding the wash liquid to this moist residue a considerable reduction of the alcoholic strength will take plaoe and somewhat low results may be expected. In analysis 1 below the ordinary wash liquid (10 c.c.) was used to pour on the residue and decanted whilst in analysis 2 absolute alcohol (10 0.0. oontaining 0.2 per cent.Ha103 was used to compensate somewhat for the reduction in the strength of the alcohol the remaining washings etc. being carried out with the usual wash liquid : 1. Taken 0-1072 grm. K,SO,. Found 0.1066 grm. Filtrate 25 O.C. 2. Taken 0.6704 grm. K,S04. Found 0-6664 grrn. ]Filtrate 30 C.C. i t will be noted that these results are somewhat low for the reason given above. Davis using 0.100 grm. K2S0, recovered 99-1 per cent. in two ~ltses. Davis’s results on a solution containing 0-04 grm. KC1 + 0.01 grm. &SO were fairly satisfactory but in stating that it is not always neceesary to remove sulphate, he completely overlooked the fact that this removal is necessitated by the insolubility of sodium sulphate in alcohol and that sodium sulphate is not decbrnpofled into sodium perchlorate by evaporating with perchlorio acid.The reason for thia difference in behaviour is easily found in Berthollet’s law. Potassium perohlorate, being the more insoluble salt is precipitated while the opposite is the oase with hhe aodium salt sodium perohlorate being more sduble thm tihe snlphab 362 MORRIS A STUDY OF THE DETERMINATION OF POTASSIUM It is fairly evident then that if we take a mixture of potassium sulphate and sodium chloride high results may be expected owing to the sodium sulphate being formed. To prove actually by experiments that such is the case the following analyses were carried out : 1. T&en 0.2627 grm. K,SO,+0*06 grm NaCl Found 0.3099 grm. K,SO,. Error + 0-0479 grm. 2. Taken 0.2592 grm. K,S0,+0-05 grm.NaCl. Found 0.2975 grm. K2S04. Error + 00383 grm. On calculating the NaCl taken into its equivalent of sodium sulphate it was found that this figure came within a few milligrams of the difference between the potassium perchlorate actually weighed and the theoretical amount of perchlorate. It seems oonclusive that the error shown in the results is due to the presence of normal sodium sulphate. It is important to notice that evaporation of a solution of sodium sulphate with perchloric acid leaves the sulphate of sodium quite unchanged. I! Prssence of Ferric SaEts.-Taken 0-3447 grm. KC'L+O*I FeCI,. Found 03445 grm. KC1. The solution was evaporated with perchlorio acid twice and in the second evaporation was taken nearly to complete dryness treated with 10 C.C. of wash liquid, decanted and the perchlorate transferred as usual without a previous re-crystal-lisation.It was noticed that the yellow colour of the solution gradually became weaker &EL the solution approached dryness and that in the second evaporation the solution was ColourIess throughout. The residue obtained was pure white but on treating with the wash liquid the strong yellow colour of the solution reappeared. After washing and drying the perchlorate was perfectly free from any yellow tinti. It seems obvious then that no possible contamination of the perchlorate with ferric oxide need be feared. Aluminium perchlorate also is perfectly soluble. It is possible however that any overheating of the dry residue might lead to high results in the oase of iron and aluminium.But if the solution is evaporated as described above there would seem to be no possibility of this occurring. Im Presme of Citric a d Tartaric Acid.-Caspari stated that the process is suitable in such cases and therefore some trials were made on a specially purified potassium hydrogen tartrate (free from trams of calcium and sulphates). On carrying out the process as usual it wag found that in trying to evaporate. off the perchloric acid the m&ss swelled and turned brownish-black. In another trial the solution was evaporated 8s fax as possible on the water-bath then transferred to the air-oven at a temperature of about 110' C. Even at that temperature the charring commenced. The following result W&8 obtained by using a very slight excesa of perchlorio acid over the theoretical amount (0.5 c.c.) and the solution WELS evaporated as frmr a8 possible on the water-bath only.The residue was still semi-fluid; 10 C.O. of pure 98 per cent. aloohol were added and decanted. The transference and washing were then aarried out with the usual washing fluid. The results are low as must be expected since the perchloric acid cannot be concentrated very far on the water-bath. In this cam it would seem preferable to apply the eobaltinitrite process for the Filtrate 32 O.C AS THE PERCHLORATE AND THE SEPARATION FROM BODIUM ETC. 363 prdpitation of the potash treating the precipitate then obtained with percbiorb &cia &I usuaJ but no trial of this process was made. Taken 0*1005 grm. KHC4E40,. Found 00994 grm. Filtrate 30 C.O.Citric acid behaves similarly to tartaric acid in the evaporation. Amdysis of Samples supplied by MT. Bertram BZount.-Early in 1919 a selec%ion from the results of Tables I. and 11. was sent to Mr. Blount with the request that he would send a few samples on which to check the degree of accuracy obtainable by the procedure given. Mr. Blount kindly sent some samples. Nos. 1 and 2 were stated to be mixed ohloridea of potassium and sodium. Sample 1 was anelysed mi received; transferred from the sample tube to a weighing bottle and the amounts taken weighed off by difference. The following remlts were obtained : No. 1. KCI per cent. 36-43 36.13 36-66. Samples Weighed off separately. Equal Volumes of the same Solution used. 36.14 36.32 36-11. Average of six results .. . . 36.30 per cent. By platinum process (Mr. Blount) . 36-40 per cent. As the above six individual results showed rather a wide divergence between the minimum and maximum found the whole of sample 2 was rapidly mixed in a mortar before transferring to a weighing-bottle and a11 the weighings-off were done immediately. The results on Sample 2 were : No. 2. KCl per cent. 75.64 75-38. 7545 75.56 75.62. Samples Weighed off sepamtely. Equal Volumes of same Solution need. Average of five results . 7553 per cent. KCl. By platinum process (Mr. Blount) '75.53 per cent. KCI. S~T&S A B C D. Determination of KCl and NaCl in a solution containing also &lorides of Al Mg and Ca. This was done in order to show what results might be expected in the determination of the alkalis in a somplex mixture after removing all other bases and isolating the mixed alkaline chlorides; and to compare results with t p direct determinahion of the potash without previous removal of the other bases.Great care was taken to eliminate the Ca Mg eto. as completely as possible before weighing mixed ohlorida, and after the weighing the Chlorides were dissolved in a little water and any r e ~ d u e ignited weighed and its weight deduoted from the weight of mixed chlorides. Silica beakers were used for the precipitations involved and the solution of the dkaline ehlorideB was evaporated in a large quartz dish. Remilts were correctea €or the sodium chloride found in blank determination on the water and reagents of which measured amounts were used in the analyses.19.96 C.C. of solution taken = 0-1805 grm. KC1 0.1917 grm. NaCl ( = 0.3722 grm. NaCl+ KCl) 0*005 grm. Al 0.04 grm. CaCO, 0.04 grm. MgO in hydrochloric solution. In A magnesium was removed by barium hydroxide. In B magnesium was removed by alcoholic ammonium carbonate (Goooh and In C one grm. of HaS04 added to the solution measured off; presipitttted by Eddy). BaCI at beginning. Magnesium removed by alooholio ammonium carbonate 364 MORRIS A STUDY OF ?HE DETERMINATION OF POTASSIUM 0~1803,0*1807,0*1812 0*1823,0*1819 O.1740,O-1761,0*1773 0*1814,0~1815 In D Direct determination of potasb. In A the results approaoh the theoretical quantity ; in B a little higher. In C the results me low but this is unavoidable owing to the inevitable adsorp-tion of a,lkaline chlorides by the barium sulphate.If the precipitation of sulphuric by benzidine could be applied in such cases it would be an advantage. Here also the cobaltinitrite process and subsequent treatment of precipitate by perchlorate process may be ueed (cf. Bennett loc. cit.). In D the results show that the direct determination of potash gives good results. O.1913,0*1924,0~1913 0*1915,0*1917 0*1897,0*1887,0*1917 -A B C D L_ KO1 + NtLCl found (Grm.) 0*3716,0*3731,0.3725 0*3738,0*3726 @3637,0*3648,0*3690 -i NaCl by Difference KC1 found (Grm.). I (Grm.). Mean KC1 (Grm.). 01807 0.17 58 0.1814 om21 Mean NaCl (Grm. ). 0.1917 0.191 1 01900 Nota.-The results under G oonfirm the general conolusion that more potash is adsorbed by barium sulphate than soda.Solzlb&ty of Potasskn Perchlorate in the wmhkg Solu,tion.-The following table gives the results of some careful determinations of the solubility of potassium perchlorate in the washing fluid made as described and containing 9T per cent. alcohol and 0.2 per cent. HClO : Solubility b7 Weight in Werght. loo 14O 15O 1706~ 24O 26.5' 2 *3 3.2 3.9 4.1 7 -3 11.1 -1 - I 2.9 3.9 4.8 5.1 9.1 13.6 1 47,000 1 32,000 1 26,000 1 24,000 ' 1 14,000 1 9,000 1 35,000 1 25,000 1 21,000 1 19,000 1 11,000 1 7,500 I t I I The figures by weight in weight have been cailculatad taking'the sp. gr. of the washing fluid as 04307. Most of these results are the average of two closely wreeing duplicate estima-tions and the figures ere a very fair approximation to the truth when the small amounts of substance actually present are t&en into consideration.All results were eblained by evaporating 100 c.0. of the saturated solution filtered at room tempera-tnre to dryness transfarring the residue by mmns of a little hot water to a plafinum-shaped quartz oruoible evaporating adding a drop of sulph-uric add igniting strongly, and weighing as sulphab This last procedure is neoeasary owing to the separatio 366 MORRIS A STUDY OF THE DETERMINATION OIP POTABSIUM: KC104 Disaolvedl Per 100 C.O. (Average.) Thin and Gumming using wash liquid containing 97% per cent. alcohol Thin and Gumming using wash liquid of pure 98.8 per oent.alcohol (The amount of KClO in the Gooch was 0.37 grm. and temp. 2P to 22" C.) Davis using wash liquid containing 94 per oent. alcohol and 0.2 per cent. and @2 per cent. HClO found . t r . . . 1.3 mgrms. . . . . . . . 4.7 b u d . . HCIO found . . . . . . . . 53.4 )). Davb using wash liquid of pure 95 per oent. aloohol found . . 14.6 (Weight of precipitate and temperature not given.) Oomparkon of Platinum with Perchlorate PTOC~SS as regards Loss in WashiV--Davis found that 100 C.C. of 80 per cent. alcohol dissolved out in washing 4.52 mgrma. EC,PtCl, equivalent to a loss of 1.3 mgrm. KC1. Now the highest loss of perchlorate I have found per 100 C.C. of washing fluid used = 2-1 mgrms. (at 2l0 O.) equivalent to a loss of 1.1 mgrrh. KC1. (Working at 15" C.the loss [perchlorate process] would be about 0.7 mgrm. KC1.) Evidently the use of the wash liquid described in this paper makea the perchlorate procese quite a8 aocurate as the platinum one and in both cases washing with exoessive amounts of liquid will tend to make the resultg low. Loss on Wadkg KCIO with a Mixture in Equal VOI'IL'IIIRS of above Wmhiv Led a d Pure Et7zer.-KC1O4 present 0.64 grm. Time of filtration six minutes. Loss per 100 C.C. at 1 4 O C. 0*0008 grm. ; 'at 15-5" C. 0.0008 grm. These figures show a considerable reduction in the solubility when compared with A above. In this last mixture I find that sodium perchlorate dissolves freely and rapidly. My thanks are due to Mr. Blount for his helpful interest in this work and elso These analyses were oarried out in the laboratory of Messrs.R. Fry and Co. Ltd.% for his kind permission to give hi8 results as obtained by the platinum process. of Brighton. ADDITIONAL NOTE ON THE OFFICIAL METHOD FOR FERTIMSERS 1918. (Leupet 18 of the Board of Agrkultwre and Fisheries.) Since 1918 the perchlorate method has been given as an alternative to the A preliminary treatment preparation of the solution for potash estimation. 1. Potash Salts containing Szllpkcctss.-The solution is precipitated by barium ohloride end the excess of this removed by the least possible excess of sulphuric acid. An aliquot part of the filtrate is evaporated with hydrochloric residue dis-solved filtered and submitted to either the platinum or perchlorate process. Criticism-This ie a correct treatment if the platinurn process is used but if perchlorate method is used it is better to allow the alight exce~s of barium chloride to remain or else traoes of the suIph&tes of eodium oalcium and ma,gnesiurn may be platinum process.I here summarise the details and append criticisms AS THE PEHCHLORATE AND THE SEPARATION FROM SODIUM ETC. 367 found with the perchlorate weighed. Attention is again drawn to the presenoe of tmes of barium sulphate in the precipitate in such cases. 2. For flue dusti guaoos and mixed fertilisers. The prepamtion of the solution will eliminate nearly everything but sodium and potaeeiurn arid may be regarded as eatisfectory. B. Perchhlorate Procest~.-Two evaporations with perchlorio aoid are presoribed till white fumes are copiously evolved," 20 c c .of 95 per cent. to 96 per cent. dcohol are now added. After stirring and allowing to settle the liquid is deoanted draining off as completely as possible; a saturated solution of potassium perchlorate in pure alcohol of same strength is used to transfer and to wash precipitate oompletely. Drying temperature 100" C. Cdicism-The repeated evaporation with perchloric acid is a good feature-Final evaporation to dryness or till fumes of perchloric scid have nearly ceased would be an improvement. A higher percentage alcohol 97 per cent. at least should be used. The method I have described is preferable-viz. evaporation to dryness. treatment with 10 C.C. of 97 per cent. alcohol containing 0-2 per cent. perchloric acid, decantation warming to drive off alcohol redissolving in boiling water and again evaporating a second treatment with 10 C.C.of the same liquid deeanting off, tmnsferring by use of the filtrate to a Goooh and finally washing with the same perchlorio alcohol in small portions (altogether 10 to 15 C.C. for final washings), and drying at 130" C. If however suitable apparatus for drawing off the filtrate is not available then the process may be followed up to the seoond decantation and for the rest of washing a Saturated solution of potassium perchlorate in alcohol preferably containing 97 per cent. and 0.2 per cent. perchlorio acid is used. The precipitate is filtered off on a Gooch crucible and dried at 130° C. If filter papers are used then a neutral solution of potassium perchlorate in alcohol must be employed (to wash out the traoes of perchlorio remaining) and the drying temperature should be about 120" C.-i.e.as high as the paper will stand without charring. Ten C.O. of 97 per cent. alcohol dissolve about 2 grms. of sodium perchlorate and alkaline earth perchlorates are also easily soluble. Therefore much washing is unnecessary. It is important if the official process is used that the 20 C.C. of alcohol added should be drained off very completely before the perohlorate solution in pure alcohol is added Otherwise the trace of HCLO remaining will precipitate 2 to 3 mgrms. of KC10 from the washing solution. This possibility is avoided if the perchlorate wash solution is made with alcohol oontaining perchloric acid. A moderate excess of perchloric aoid is suffioient for official process; 10 C.C. of 20 per cent. perchlorio will generally suffice for one gram of substance taken. It is best to uee pure duty-paid alcohol. Industrial methylated spirits (strongest) contain an indefinite amount of water and are also too dilute. Joseph and Martin (J. Soc. Chm. Id. 1920 39 91,) record a violent explosion on ooncentrating the filtrate from the perchlorate precipitate to low bulk in order to estimate sodium directly in the ash of papyrus. There does not seem to be any danger in the determination of potassium and Sohloessing determined the NaCl in mixtures of pure KCl+NaCl by evaporation of the filtrate from th 368 ABSTRACTS OF CHEMICAL PAPERS ]pot& and finally weighing 8s the sulphate of sodium apparently without acoidenti. NoTE.-While Baxter and Kobayashi have ehawn that at O* C the solubility of potassium perchlorate in alcohol containing 0.1 per oent. HCIO is practirsdly the same as in aloohol containing 0.2 per cent. still their own fignree for the solubility at 21' C. ahow that the 0-2 mixture dissolves less than the 0-1 per cent. mixture at room temprratzlres

ISSN:0003-2654    

DOI:10.1039/AN9204500349

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C.of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem.Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ...... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C.of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w.P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust.The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9204500368

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C.of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem.Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ...... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C.of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w.P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust.The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ...... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9204500373

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C.of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem.Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ...... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C.of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w.P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust.The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ...... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C.basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C.of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene.w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins .. . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9204500379

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C.of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem.Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ...... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C.of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w.P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust.The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ...... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9204500388

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C.of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem.Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ...... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C.of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w.P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust.The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9204500394

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C.of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem.Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ...... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood. The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather.The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent. of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C.of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed.The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed.The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.ORGANIC ANALYSIS 325 Soluble d i d s ... ... ... Non-thmins . . . ... Tannin ... ... . . I I - 1--- Percent. I Per Cent. Per Cent. 2.76 4-77 25-7 1-89 3.63 13.5 0.86 1-15 12.2 Heartwood.The only part of the wood which 4as any possible value as a souroe of tannin is the heartwood; the chief available raw material would be the sawdust. The tannin imparts a dark purplish-brown colour to the outside of hides, but the leather produced might be satisfaotory as a heavy sole leather. The liquor which oolIects an steam-kilning the wood contains from 7 to 10 per cent.of tannin. W. P. S. Estimation of Thiophene. P. E. Spielmann and S. P. Schotz. (J. Soc. Chem. Id., 1919,38,188-189T.)-The authors have examined various met-hods whioh have been suggested for the estimation of thiophene in benzene, and recommend the following modifioations of the basic mercuric sulphate and acetate methods : Basic Mercu/l.ic Szi,&hate Method.-Two C.C. of the benzene and 20 C.C. basic mercuric sulphate solution (sulphuric acid 20 c.c., water 100 ox., and mercuric oxide 5 grms.) axe shaken in a closed tube for three hours; the white precipitate which is formed is collected, washed with hot water, dried at 110" C., and weighed. The weight multiplied by 0.0757 gives the amount of thiophene in 2 C.C. of benzene. Basic Mercuric Acetate Method.---Ten O.C. of the benzene and 4 grms. of baaic mercuric aaetafe (mercuric oxide, 1 part, glacial aceti0 said, 2 parts, the mixture b~iing filtered and the salt washed with ether) are heated on a water-bath under a, reflux condenser for fifteen minutes ; after cooling, the precipitate i8 collected, washed with water, dried at 100" C., and weighed. The weight is multiplied by 0.07516 to obtain the oorresponding amount of thiophene. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9204500400

出版商:RSC    

年代:1920

数据来源: RSC