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Liquid-vapor phase equilibrium in solutions of oxygen and nitrogen at pressures below one atmosphere

1955; US government; Volume: 55; Issue: 5 Linguagem: Inglês

10.6028/jres.055.031

2376-5305

George T. Armstrong, Jack M. Goldstein, D.E. Roberts,

Gas Dynamics and Kinetic Theory

A cryostat and equilibrium vessel, together witI: auxiliary ap.p~ratus for.establis hi~lg equilibrium between liquid and vapor pl.1~s e~ of SOlutlO!lS of low bOllmg mat~nll;ls by a ?ll'culation method, is described.The eqUllIbnum vessel mcorporates a n ovell~qUld samplmg device.Vapor and liquid compositions and t otal ;;apo~ press Ul'~s of s o,lubons.<!f oxyge.nand nitr ogen were measured along isotherm s at 77.5 ,70 and 65 K .1he actIvIty coefflcients of nitrogen and oxygen may be represented by equations of t he forlll in which AI2 in cal /cm 3 rnoic has the values 1.22 at 77.5°, 1.38 at 70°, and 1. 47 at 65° Ie The deviations of the solutions from ideality a re much less t han is to be ex pected of regular s olutions, in which the interaction e nergy betwecn unlike molecules follows a geometric mean law.The data are not entirely consistent with the assu mpt ion t hat molar volum e ar e additive in t he solu tions.1 This work was