![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
One method for determination of the second virial coefficient B of pure materials involves the use of the Clapeyron equation with independently measured values of the heat of vaporization , the molar volume Vsat of the saturated liquid, and the vapor liquid saturation pressure Psat .