Thermodynamics of binary solutions of nonelectrolytes with 2,2,4-trimethylpentane. IV. Vapor-liquid equilibrium (35-75°) and volume of mixing (25°) with carbon tetrachloride

The vapor-liquid equilibrium in the 2,2,4-trimethylpentane-carbon tetrachloride system was measured isothermally at 10° intervals in the range 35-75° and over the entire range of composition. The volume of mixing was measured at 25° and the maximum was 0.218 cm3 mol-1. The excess thermodynamic functions were calculated for the conditions of mixing at constant pressure and were found to be positive over the entire range of composition and temperature studied and small in magnitude (at 40° maxima are ΔG̃pE = 35.0 cal mol-1, ΔH̃pM = 44 cal mol-1, and ΔS̃pE = 0.23 cal mol-1 deg-1). The excess Gibbs function decreases slightly with increasing temperature, but the other functions are independent of temperature within experimental error. The constant volume thermodynamic functions are almost identical with the constant pressure functions. Good agreement was found with a theoretical treatment proposed by Flory and coworkers.