The following derivation for the residual Enthalpy equation was provided to me by my Thermo professor. This derivation will be evaluated in our final exam. What I don’t understand is how step 8 is achieved. The professor explained this step on the board which is the scribbles you can see to the left. Could anyone shed light to this problem? I can’t understand what my professor says. The professor appears to have used some sort of logarithm property to achieve this but I have no clue. Thanks in advance.
