The Compressibilities of Gaseous Mixtures of Methane and Normal Butane. The Equation of State for Gas Mixtures

Abstract
The compressibilities of three gaseous mixtures of methane and normal butane have been measured from 100° to 300°C and from 1.25 to 10 mole/liter (maximum pressure 350 atmos.). The data on these three systems and the two pure hydrocarbons are used to study several methods of combination of constants in the Beattie‐Bridgeman equation of state extended to apply to gas mixtures. The best results were obtained with square‐root combination for A0 and for c and Lorentz combination for B0; but square root combination for A0 and linear combination for B0 and for c are a fair compromise between accuracy of representation of the data on mixtures and simplicity of expression.