1. The problem statement, all variables and given/known data A liquid is in equilibrium with its vapor at its boiling point. On an average, the molecules in the two phases have equal: (A) inter-molecular forces (B) potential energy (C) total energy (D) kinetic energy 2. Relevant equations 3. The attempt at a solution I know (A) is wrong as intermolecular forces in liquids are much more than those in gases. However, I'm confused between (B) (C) and (D). I know in gases KE is directly proportional to temperature. I'm not really sure about anything beyond this.