Heat stuff?

Question

Can someone explain why the heat capacity of a liquid at its boiling temperature is generally a lot larger than the heat capacity of its vapor at the same temperature

Answer 1

The heat capacity is a measure of the amount of heat that can be "stored" in a substance. So, you need to look at where that energy can be stored. Some of it can be stored in the intra-molecular bonds, that which keeps a liquid from becoming a gas. Once a substance vaporizes, the molecules are no longer connected to each other, so those bonds cannot store any energy, and the heat capacity decreases.