Calculate Latent Heat: L = (S_after - S_before)T

[KFC]

We could use the change of entropy before and after eh phase changed to calculate the latent heat

<br /> L = (S_{after} - S_{before})T<br />

and in some case, if we know the relation of pressure and temperature, we can also apply Clausius-Clapeyron relation to calculate the latent heat.

I wonder if there is any usual way to calculate the latent heat for phase change. If the pressure is unchanged we see that then change of enthalpy is same the

\Delta H= T\Delta S

So can I say the latent heat of phase change b/w any two phase for any system is equal to the change of enthalpy of this system during the phase change?

 

[olgranpappy]

Yes, it's okay since the transition occurs at constant temperature and pressure.

<br /> L\equiv\Delta Q = T\Delta S=\Delta H - V\Delta P=\Delta H\;.<br />