Latent heat of Condensation is associated with which phase change?

• A. Liquid to solid
• B. Solid to gas
• C. Vapor to liquid
• D. Liquid to gas

Answer: (C)

Latent heat of condensation is the energy released when a substance changes from a gas to a liquid at a constant temperature. This is the phase change from vapor to liquid, not melting, sublimation, or vaporization.

In refrigeration, when ammonia gas leaves the compressor and enters the condenser, it releases this latent heat as it condenses into a liquid, transferring heat to the condenser water or air. The magnitude of this latent heat is the same as the latent heat of vaporization but with opposite sign (energy is given off by the refrigerant).

The other phase changes are different: liquid to solid involves latent heat of fusion; solid to gas is sublimation; and liquid to gas is latent heat of vaporization (evaporation).