The latent heat of vaporization of ethanol is 200 calories/gram. This means that _____.
The latent heat of vaporization of ethanol is 200 calories/gram. This means that about 200 calories of heat must be added to 1 gram of ethanol to convert it form a liquid to a gas.
Pretty general and with no context; however, this may fit.
it requires 200 calories of energy to change the phase of 1 gram of ethanol at its boiling point from liquid to vapor.