Equilibrium vapour pressures of carbon monoxide + nitrogen solid solutions

Abstract

Vapour pressures of carbon monoxide + nitrogen solid solutions have been measured in the region of the λ-transition (55–63°K) by a condensation technique. Measurements on bulk solutions were not practicable for T < (0.9 times the temperature of the triple point) because very long equilibrium times were encountered. Equilibrium pressures for three solutions of fixed vapour concentration (7.5, 20 and 39 % nitrogen) are reported and the excess Gibbs energies have been derived as a function of temperature. Deviations from ideal behaviour are small in both the α and β solid phases. Conventional vapour pressure measurements on a bulk specimen of pure carbon monoxide (∼1 cm³) are also described and the results compared with those of other workers; the agreement is good.