Second virial coefficients of fluorinated methanes CH4−xFx (x = 0–4) and their binary mixtures

Abstract

We report on measurements of second virial coefficients of all fluorinated methane compounds CH_4−xF_x (x = 0–4) in the temperature range from 296 K to 463 K and of second interaction virial coefficients of all their binary mixtures. Most of the mixtures deviate strongly from the behaviour of ideal mixtures, the most extreme example being the mixture CH₃F–CHF₃, where the interaction virial coefficient is remarkably more negative than the virial coefficients of both components. Arguments that allow overall qualitative understanding of this behaviour are presented.