THE SOLUBILITY OF P-XYLENE IN WATER AS A FUNCTION OF TEMPERATURE AND PRESSURE AND CALCULATED THERMODYNAMIC QUANTITIES

Abstract

An experimental approach was developed to measure the mutual solubilities of organic fluids and water over a wide range in temperature and pressure. By using a gold bag, rocking autoclave, and a precision high pressure liquid chromatography pump, samples of both equilibrated fluids may be obtained. Using this technique the solubility of liquid p-xylene in water was measured as a function of temperature and pressure from 298 to 423 K (at constant pressure) and from 0.1 to 50 MPa (at constant temperature). The results were used to calculate the partial molal thermodynamic quantities: ΔGsoln, ΔHsoln, ΔSsoln, ΔCpsoln, and ΔVsoln. Calculated values for these quantities at 298 K are: ΔGsoln = 15.92 (+/-.13) kJ/mol, ΔHsoln = 1.643 (+/-.214) kJ/mol, ΔSsoln = -47.90 (+/-.72) J/mol-K, ΔCpsoln = 214.7 (+/-3.8) J/mol-K, and ΔVsoln = 31.08 (+/-3.80) cm3/mol.