An empirical equation is given for the isothermal variation with density of the work content of pure hydrocarbons in the gaseous or liquid state. From this fundamental equation are derived (a) an equation of state, (b) an equation for the fugacity, and (c) an equation for the isothermal variation of the enthalpy. These equations summarize P-V-T properties of the gaseous or liquid phase, critical properties, vapor pressures, and latent heats of evaporation. A procedure is suggested for determining numerical values of the parameters in the equation. Such values are given for methane, ethane, propane, and n-butane. A comparison is made between observed properties of these hydrocarbons and those predicted by the equations.

An empirical equation is given for the isothermal variation with density of the work content of hydrocarbon mixtures in the gaseous or liquid state. From this fundamental equation are derived (a) an equation of state, (b) an equation for the fugacity, (c) an equation for the isothermal variation of the enthalpy, and (d) an equation for the isothermal variation of the entropy. These equations summarize P-V-T-x properties of the gaseous or liquid phase, liquid-vapor equilibria, critical properties, latent heats of evaporation, and heats of mixing. The equation is a generalization to mixtures of the equation for pure hydrocarbons given in the first paper of this series. Methods are proposed for determining the parameters in the equation for mixtures from the parameters in the equation for pure hydrocarbons. A comparison is made between observed properties of mixtures and those predicted by the equations. These comparisons show that the equations provide a satisfactory practical summary of the volumetric properties and liquid-vapor equilibria of mixtures of methane, ethane, propane, and n-butane.

Liquid-vapor equilibrium data are presented for the system methaneethylene-isobutane at 37.78°and 71.11" C. and 34.02 and 68.05 atmospheres. The data are shown to be in satisfactory agreement with the predictions of a previously published empirical equation of state for light hydrocarbons.

No abstract

No abstract