Bruce E. Gammon

Experimental densities for compressed R134a

Abstract This paper reports densities of compressed R134a (1,1,1,2-tetrafluoroethane) determined by using a contiuously weighed pycnometer at 20 K intervals between 180 and 380 K at pressures from slightly greater than the vapour pressure to 70 MPa. The results are accurate to within ±0.1%. Saturated liquid densities derived by extrapolation from the experimental values agree with other reported values to within ±0.3%.

A thermoelectric flow enthalpy-increment calorimeter

Abstract A flow calorimeter for measuring enthalpy increments of fluids from 200 to 500 K and at pressures to 20 MPa has been constructed. It was tested with measurements on water, p-xylene, and n-heptane. Results are within ±0.5 per cent of literature values.

Vapor pressure of trichlorofluoromethane

Abstract We have used a semiautomated isochoric apparatus to measure the vapor pressure of trichlorofluoromethane (R-11) from 353.15 to 378.15 K, and have compared our results to values in the literature. After evaluating the measurements with weighting to account for experimental accuracy, we have established a recommended vapor pressure equation and a critical pressure P c for R-11.

Enthalpies of water + methanol mixtures between 180 K and 320 K

Abstract Enthalpy increments relative to 298.15 K were measured using a thermoelectric flow calorimeter for six water + methanol mixtures between 180 K and 320 K. Excess Gibbs energies were derived as a function of temperature and composition from the measured enthalpies and vapor-liquid equilibrium results reported in the literature. The excess Gibbs energies are calculated relative to hypothetical liquid water below 273.15 K; the properties of the hypothetical liquid also are reported.