摘要:

The infrared absorption spectra of thiazole, all three monomethylthiazoles, and two dimethylthiazoles have been measured in the liquid phase.

ISSN:0008-4042    

DOI:10.1139/v57-061

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Identical values of the bimolecular rate constant of the ferrous ion – hydrogen peroxide reaction were obtained from intercomparisons of the methods previously used in following this reaction. In perchloric acid the bimolecular rate constant is unaffected by acid concentration; in sulphuric acid it increases slightly in acid concentrations above 10−2N. The results agree with and explain the differences between those obtained by Baxendale and by Dainton, but are only in marginal agreement with those recently reported by Weiss.

ISSN:0008-4042    

DOI:10.1139/v57-062

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

An expression has been derived for the rate of ferric ion production in the ferrous ion – hydrogen peroxide reaction in aqueous solution containing dissolved hydrogen and oxygen. It involves the relative value of the rate constants for the intermediate reactionsThe effects of side reactions involving the intermediate hydroperoxyl radical are considered. The rate calculated from the derived expression agrees with that measured experimentally (±2%). When carbon monoxide is used instead of hydrogen, the kinetic scheme and rate expression are the same. The agreement between experimental and calculated rates is within ±2%.

ISSN:0008-4042    

DOI:10.1139/v57-063

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Approximately 10–20% yields of alpha-ureidopropionamide and alpha-ureidoisovaleramide were obtained as major by-products in the synthesis of 5-methylhydantoin and 5-iso-propylhydantoin, respectively, by the Gaudry (3) technique. The two compounds can be hydrolyzed to their corresponding amino acids, DL-alanine and DL-valine, in alkaline solution or recyclized to their corresponding hydantoins with mineral acid.

ISSN:0008-4042    

DOI:10.1139/v57-064

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

Alloys of cobalt and arsenic containing up to 60% As by weight have been studied by means of room temperature and high temperature Debye–Scherrer diagrams. Two compounds exist at room temperature, Co2As and CoAs, both of which undergo crystallographic transformations at higher temperatures, the former between 400 °C. and 500 °C., the latter at about 950 °C. A third compound, probably Co3AS2, is formed by the reaction of Co2As with CoAs above 940 °C. The structures of these compounds are compared with the structures of the corresponding compounds in the iron/arsenic system. These results indicate the necessity of slight revisions to the Co/As diagram, and raise serious questions in respect of the validity of decomposition pressure data reported recently for cobalt arsenides.

ISSN:0008-4042    

DOI:10.1139/v57-065

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The dielectric properties of methanol and methanol-dwere examined between liquid nitrogen and room temperature at frequencies between 40 and 106cycles per second. In addition to the large increase in the dielectric constant within solid CH3OH at 159.6°K., there is evidence of a further, gradual transition at about 155°K. Similar changes in CH3OD occur at 163.2° and about 157°K. Dispersion processes within the solid are discussed in terms of misaligned crystallites and polarization at the interfaces between crystallites and between regions of solid and liquid. Conductance maxima near 130°K. are tentatively related to the methanol–water eutectic. Static dielectric constants of liquid CH3OD are a little lower than those of CH3OH, while relaxation times over a limited temperature range above the freezing point are some 35% higher; the activation energies for dielectric relaxation of the two molecules in the liquid state are approximately the same (3.5 kcal./mole).

ISSN:0008-4042    

DOI:10.1139/v57-066

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The theory of flame propagation in ozone–oxygen mixtures developed in earlier papers of the author is applied to mixtures containing 50%–100% ozone. The formulae are modified to allow for comparatively high concentration of atomic oxygen. The results are found to be in very good agreement with experimental values which have recently become available.

ISSN:0008-4042    

DOI:10.1139/v57-067

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The analytical reagent "tiron" undergoes oxidation in alkaline solution by the oxygen of the atmosphere to a yellow-colored substance, which is assumed to be the corresponding quinone. In certain circumstances the reagent may be oxidized with production of a green substance believed to be a semiquinone. Interference in the colorimetric determination of iron by means of this reagent may occur in alkaline solution owing to the overlap of the iron III derivative and of the oxidation product. Alkaline solutions of tiron react with iron II salts even in the rigorous absence of oxygen to form the iron III tironate FeR3−9. Oxygenated solutions of tiron in alkali fail to produce this compound with iron III salts, but do so with iron II salts.

ISSN:0008-4042    

DOI:10.1139/v57-068

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The B-bands of a number of ring substituted acetophenones were determined. The observed changes are discussed in relation to the nature and position of the substituent group and are compared with the corresponding changes observed in the infrared carbonyl stretching bands.

ISSN:0008-4042    

DOI:10.1139/v57-069

出版商:NRC Research Press    

年代:1957

数据来源: NRC

摘要:

The addition of hydrogen bromide to 1,1-dichloroethylene under ultraviolet illumination gave two products identified as 1-bromo-2,2-dichloroethane and 1-bromo-2,2,4,4-tetra-chlorobutane. With deuterium bromide, the corresponding deuterated halides were formed. 1-Chloroethene-1-dwas prepared from 1-bromo-2,2-dichloroethane-2-d.

ISSN:0008-4042    

DOI:10.1139/v57-070

出版商:NRC Research Press    

年代:1957

数据来源: NRC