Methods for Determining the Second Virial Coefficient of a Gas from Speed-of-Sound Data

Abstract

Two methods of analyzing speed-of-sound data in gases to obtain the second virial coefficients $B\left(T\right)\mathrm{}$ are compared. The older method, which assumes a form for the temperature dependence of $B$, is shown to correspond to finding an exact solution to an approximate differential equation for $B$, while a method recently proposed by Bruch solves the exact equation, but in an approximate manner. Examination of the errors in each method indicates that the first method is preferable.