Final answer:
The heat of vaporization is the quantity of heat a liquid must absorb for 1 gram to be converted from a liquid to a gas. It is usually expressed in joules per gram or joules per mole. The heat of vaporization of water is approximately 2,250 J per gram.
Step-by-step explanation:
The quantity of heat a liquid must absorb for 1 gram to be converted from a liquid to a gas is called the heat of vaporization. It is usually expressed in the units of joules per gram for the unit amount in grams or joules per mole for the unit amount in moles. The heat of vaporization is a specific property of a substance and can be used to calculate the total heat being transferred for vaporization or condensation.
The heat of vaporization of water is about 2,250 J per gram, meaning that every gram of water that goes from liquid to gas requires an energy input of approximately 2,250 J.
Example: If you have 8.0 × 10² g of water and you heat it from 21 °C to 85 °C, you can calculate the amount of heat absorbed using the specific heat of water and the change in temperature.