1. The problem statement, all variables and given/known data Determine the vapor pressure of water at 50 degrees C. The molar heat of vaporization of water is 40.7 kJ/mol. 2. Relevant equations Clausius-Clapeyron equation. 3. The attempt at a solution P1 = 760 mm Hg T1 = 373 K P2 = ? T2 = 323 K ln (P2/760) = ln P2 - ln 760 = -(40700/8.31)(1/323 - 1/373). I'm taking the change in temperature (delta T, or final minus initial temperature, and accordingly I put a negative out in front of the right side of the equation). ln P2 = 4.6 e^4.6 = P2 = 100 mm Hg (approximately). Is this correct?