摘要:

The total vapour pressures of binary mixtures of hydrogen peroxide and water have been measured by means of the static method at 30, 45, and 60 °C. over the entire range of concentration. The vapour-pressure–composition curves have been found to exhibit large negative deviations from Raoult's law, but no minimum. A special apparatus and experimental technique were devised that enabled the composition of the vapour to be determined in each case. These data were used to obtain the partial pressures of both components. The values thus found are in good agreement with those calculated from the total vapour pressures by means of the Duhem Margules equation. The activities of water and hydrogen peroxide in their solutions have been calculated and interpreted on the basis of the polarity of the two pure liquids.The normal boiling point and latent heat of vaporization of the solutions were obtained by extrapolation of the vapour pressure data. The results are important in connection with the distillation of aqueous solutions of hydrogen peroxide.

ISSN:1923-4287    

DOI:10.1139/cjr40b-023

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

Empirical equations describing the behaviour of wheat protein films studied by means of the hydrophil balance technique are presented. Evidence is given which shows that the protein forms a gel when the film area is decreased and that degelation occurs when the area is expanded. A theoretical picture of gel structure is developed to account for the phenomena characteristic of gelation and degelation. Two major assumptions are used: the protein micelles in the gelled condition and in the film stage are in equilibrium only when the film micelles are close packed and oriented in such a position that the binding force between the film micelles and the aqueous substrate is perpendicular to the water surface. From these assumptions the general form of the gel term is deduced and it is then shown that gels in the form of logarithmic spirals satisfy the physical and theoretical conditions.

ISSN:1923-4287    

DOI:10.1139/cjr40b-024

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

The kinetics of the thermal decomposition of ethane have been investigated by the static method in the temperature range 565° to 640 °C. The reaction was found to be uninfluenced by surface. The rate of the reaction can be expressed byThe products of the reaction are ethylene, hydrogen, and a small amount of methane and probably higher hydrocarbons.The reaction is discussed from the point of view of free radical mechanisms, and it is suggested that the results cast serious doubt on the validity of the Rice-Herzfeld mechanism and its modification by Küchler and Theile.

ISSN:1923-4287    

DOI:10.1139/cjr40b-025

出版商:NRC Research Press    

年代:1940

数据来源: NRC

摘要:

A simple automatic machine has been designed and built for delivering small measured quantities of liquid at regular intervals of time. The fluid comes in contact with no other material than glass, and hence the apparatus may be used to handle almost all known, free flowing liquids without fear of corrosion of the apparatus or serious contamination of the fluid. The liquid may contain a solute or stable colloidal particles without causing irregular operation through the deposition of solids by evaporation. The design lends itself particularly to handling many different fluids simultaneously, or to delivering measured quantities of a similar fluid at many different places.A machine substantially similar to the one described in this paper, handling 12 different fluids at once, has been in operation continuously for more than eight months, and has required very little attention apart from replenishing the contents of the reservoirs.

ISSN:1923-4287    

DOI:10.1139/cjr40b-026

出版商:NRC Research Press    

年代:1940

数据来源: NRC