1. The problem statement, all variables and given/known data What is the vapor pressure of benzene at 50.0 C? Benzene's boiling point is 80.1 C and its heat of vaporization is 31 kJ/mol 2. Relevant equations 3. The attempt at a solution I don't want to be that guy who just says "I don't know" but.. All I know is that: ln P = -(Hvap)/RT + C (and I don't know what C is besides "constant.") and ln(p1/p2) = Hvap/R (T1-T2/T1T2) but this relates the vapor pressure at different temperatures.. I am really not good at these applied things... any help is appreciated.