On a method of calculating fluidity, surface tension and reaction (equilibrium) pressure

✍ Scribed by Henry Jermain Maude Creighton

• Publisher: Elsevier Science
• Year: 1922
• Tongue: English
• Weight: 422 KB
• Volume: 193
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(22)90582-4

✦ Synopsis

SOME years ago it was shown by Ramsay and Young i that for any pair of closely related substances--such as methyl acetate and ethyl acetate, or propyl propionate and propyl butyrate--the ratio of the absolute temperatures (7") corresponding to equal vapour pressures is constant, i.e., T A/T'~ = T A ~IT B = a constant. For substances not closely related, it was found that the relation was less simple, but that it might be expressed by the equation R'=R+c(T" u -TB) , where R' is the ratio of the absolute temperatures of the two substances corresponding to any vapour pressure, the same for both; R is the ratio of the absolute temperatures at any other vapour pressure, again the same for both; and T~ and T B are the temperatures of one of the substances corresponding to the two vapour pressures. This relationship, which was tested by Ramsay and Young for 2 3 pairs of substances, has been found to hold up to the critical point. The method has been employed by Ramsay and Travers 2 to calculate the vapour pressures of the inert gases, argon, krypton and xenon, at various temperatures.

At the suggestion of Ramsay, Findlay a showed that a precisely similar equation to that of Ramsay and Young connects the absolute temperatures at which two substances have equal solubilities, and also the absolute temperatures at which two chemical equilibria have equal equilibrium constants.

The writer has found that the absolute temperatures at which two substances have the same value for certain other physical constants are related by an expression having the same form as the Ramsay and Young vapour pressure equation. In this paper the relations between the absolute temperature and fluidity, the * Communicated by Professor Creighton.