Which property is desirable in a refrigeration system to optimize energy storage during phase change?

• A. Low density
• B. High boiling point
• C. High latent heat
• D. High freezing point

Answer: (C)

Latent heat is the energy stored or released when a substance changes phase at a constant temperature. In a refrigeration system, you want to maximize how much energy you can store during that phase change, so using a substance with high latent heat per unit mass means more energy can be absorbed or released without a rise in temperature. This makes energy storage more efficient and allows for a smaller, lighter system. The other properties don’t drive this storage ability as directly: density affects energy per volume but doesn’t change the amount of energy per kilogram handled during the phase change, while boiling and freezing points mainly set the temperature at which the change occurs rather than the amount of energy stored.