EXPERIMENTAL AND THEORETICAL-STUDIES OF THE CROSSOVER-BEHAVIOR OF THESPECIFIC-HEAT C-V,C-X OF ETHANE, PROPANE, AND THEIR MIXTURE AT CRITICAL ISOCHORES

The specific heat at constant volume, C-v, of propane, and mixture wit h a concentration of x = 0.0081 mol fraction of propane was measured a long the critical isochores at temperatures between 290 and 400 K. The measurements were performed with a high-temperature constant-volume a diabatic calorimeter. The uncertainty of most of the measurements is e stimated to be less than 1.5%. Measurements have been carried out in b oth the one- and two-phase regions. The results for the pure component s are compared with earlier measurements. Crossover equations for C-v obtained on the basis of the renormalization-group method and epsilon- expansion are applied to represent our experimental specific heat data for ethane, propane, and its mixture along the critical isochores.