Final answer:
When refrigerant vapor is condensed back into a liquid in the condenser, it releases latent heat due to the exothermic phase change that occurs during the condensation process.
Step-by-step explanation:
When refrigerant vapor enters the condenser to be condensed back into a liquid, it is giving off latent heat. During the phase change from vapor to liquid, the refrigerant releases the energy that was previously absorbed to convert it from liquid to gas. This energy release does not change the temperature but changes the state of the substance. The heat pump of a refrigeration system works on this principle, using the exothermic process of condensation to remove heat from the refrigerant and release it, typically into the outside environment.
The energy involved in the phase change from vapor to liquid is significant, and it is known as the latent heat of condensation. This energy transfer is described by the formula Q = mLy, where 'Q' is the heat transfer, 'm' is the mass of the substance, and 'Ly' is the latent heat of vaporization. As the refrigerant condenses and releases this latent heat, it transforms back into a liquid without the temperature of the substance changing.