Water standing in the open at 30.7°c evaporates because of the escape of some of the surface molecules. the heat of vaporization (550 cal/g) is approximately equal to εn, where ε is the average energy of the escaping molecules and n is the number of molecules per gram. (a) find ε. (b) what is the ratio of ε to the average kinetic energy of h2o molecules, assuming the latter is related to temperature in the same way as it is for gases