= Variable-latent-heat saturation curve
{title2=$\ln(p/p_*)=\int_{T_*}^T L(\theta)/(R\theta^2)\,d\theta$}
For a dilute <ideal gas> <vapor> whose specific volume greatly exceeds that of its condensate, the <Clausius-Clapeyron relation> integrates to the displayed formula. If $L(T)=L_*(T_c-T)/(T_c-T_*)$, the result is $\ln(p/p_*)=L_*[T_c(1/T_*-1/T)-\ln(T/T_*)]/[R(T_c-T_*)]$. Near the <liquid-gas critical point>, both the <ideal gas> approximation and the neglect of condensed-phase volume fail; zero <latent heat> alone does not determine the limiting coexistence slope.
Back to article page
