摘要:

D-Glucurono-γ-lactone,D-galacturonic acid, and potassiumD-glucuronate have been degraded in good yield toD-arabopenturonic,D-threotetruronic, andD-erythrotetruronic acids, respectively, using lead tetraacetate in acetic acid solvent as the reagent.

ISSN:0008-4042    

DOI:10.1139/v56-093

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The mercury photosensitized (Hg3P1) decomposition of olefins has been examined using a reactor coupled directly to a mass spectrometer. The primary split of ethylene has been shown to be predominantly molecular, and that of propylene mainly into an allyl radical and a hydrogen atom. With 1-butene the split is predominantly at a C–C bond giving allyl and methyl radicals, although a rupture of a C–H bond occurs as well. With 2-butene and isobutene a C–H bond is broken. It is concluded that the allyl and methallyl radicals produced have large cross sections for reaction with excited mercury atoms.

ISSN:0008-4042    

DOI:10.1139/v56-094

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Velocities of exchange of iodine between monolayers at the air/water interface of α-iodostearic acid and potassium iodide in the substrate have been measured over a range of monolayer and substrate concentrations and temperatures using a radioactive tracer technique. The pressure–area isotherms were also determined. The process was followed by measuring the decrease in counting rate immediately above the surface. It is shown theoretically that ions released to the substrate diffuse rapidly and do not contribute appreciably to the counting rate. The velocity of exchange was found to be first order in concentration of the surface phase and of higher but indeterminate order in concentration of potassium iodide. In the region of 18 °C., where a transition from liquid-condensed to liquid-expanded film occurs, the reaction velocity constant undergoes a discontinuous increase. Activation energies of 8.0 and 10.8 kcal./mole were found for exchange in the condensed and expanded films respectively.

ISSN:0008-4042    

DOI:10.1139/v56-095

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The total surface energies (or surface enthalpies) of calcium oxide and calcium hydroxide were determined by measuring the heats of solution in 2 Nnitric acid of calcium oxide and calcium hydroxide having high and low specific surface areas, and by determining the surface areas by the B.E.T. method, using nitrogen as adsorbate. The molecular area of nitrogen was taken to be 16.2 Å2at 77.3 °K. Precision determinations of the lattice parameters indicated that the high and low surface substances had the same unit cell dimensions, and X-ray line broadening measurements indicated that the crystals were perfect or nearly perfect. The surface energy of calcium oxide at 23 °C. was found to be 1310 ± 200 erg/cm.2, which compares well with the theoretical value of 1100 erg/cm.2The surface energy of calcium hydroxide at 23 °C. was found to be 1180 ± 100 erg/cm.2The heat of the reaction CaO (c, 23°) + H2O (l, 23°) = Ca(OH)2(c, 23°), for crystals having negligible specific surface areas, was found to be −15,620 cal.

ISSN:0008-4042    

DOI:10.1139/v56-096

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Several new cyclic guanidino acids have been prepared by the reaction of cyclic isothioureas with amino acids. The ethyl esters of some of these acids have been converted into dialkylaminoalkylamides by refluxing with dialkylaminoalkylamines in the presence of an inert solvent. A series of dialkylaminoethyl esters of the2-(carboxyalkylamino)-2-imidazolines also have been prepared.

ISSN:0008-4042    

DOI:10.1139/v56-097

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

An expression due to Hildebrand and Scott has been used to select silver as a possible extractant for plutonium from neutron-irradiated uranium. The distribution of plutonium between molten silver and molten neutron-irradiated uranium has been examined in small-scale experiments. The fraction of plutonium in the silver layer increases with increasing temperature. For equal weights of silver and uranium containing 0.1% plutonium, 88% of the total plutonium is distributed to the silver phase at 1350 °C. Greater proportions of plutonium are found in the silver phase in experiments with uranium of lower initial plutonium concentration. On the addition of gold to the system plutonium extraction is increased and passes through a maximum. This maximum appears to be associated with a particular concentration of gold in silver and of gold in uranium.

ISSN:0008-4042    

DOI:10.1139/v56-098

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Representative esters of methanesulphonic acid were synthesized, and cleaved to form the corresponding fluorides, iodides, and thiocyanates. From this work was developed a convenient laboratory procedure for converting alcohols to fluorides.

ISSN:0008-4042    

DOI:10.1139/v56-099

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The adsorption of nitrogen by a carbon black designated as Spheron 9 has been measured at 78 °K. and 71 °K. The second type of hysteresis previously reported for three Acheson graphites has also been observed for the adsorption of nitrogen by Spheron 9 at both temperatures. Unlike the graphite isotherms, it was possible to scan the hysteresis loop of the Spheron isotherm. The adsorption of nitrogen has been measured for an artificial graphite in which the ash had been leached out by treatment with hydrofluoric acid. The results were compared with those obtained previously for a sample of the unleached graphite. It was found that although the surface area was altered by this treatment, the hysteresis effects remained unchanged.

ISSN:0008-4042    

DOI:10.1139/v56-100

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Reaction of oxygen atoms, produced by mercury photosensitized decomposition of nitrous oxide, with acetaldehyde has been studied at room temperature. The major products of the reaction are water and biacetyl and the only primary process appears to befollowed byandAt room temperature oxygen atoms react with acetaldehyde 0.7 ± 0.1 times as fast as with ethylene, so that the activation energy of reaction [1] is likely to be close to 3 kcal./mole.

ISSN:0008-4042    

DOI:10.1139/v56-101

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The composition of the strong phosphoric acids was studied in the range 68.8 to 86.3% phosphorus pentoxide by weight. Improved filter-paper chromatography made possible the quantitative determination of the nine lower members of the series, and occasionally up to the twelfth member. It was found that when the strong phosphoric acids are prepared by heating at 350 °C, a dynamic equilibrium between the component acids is set up which persists when the mixtures are cooled to room temperature. Only linear condensed polyphosphoric acids were present in the range studied. The composition corresponding to 100% orthophosphoric acid contains about 6 mole percent each of pyrophosphoric acid and “free water”. As the mole ratio of water to phosphorus pentoxide decreases, the number of component acids increases. Orthophosphoric acid is present to an appreciable extent in the stronger phosphoric acids. “Hexametaphosphoric acid” is not a separate chemical entity, but a mixture of higher linear polyphosphoric acids.

ISSN:0008-4042    

DOI:10.1139/v56-102

出版商:NRC Research Press    

年代:1956

数据来源: NRC