ANS:C - latent

Removal of latent heat is involved in the condensation of a vapor under saturated conditions. When a vapor condenses into a liquid at its saturation temperature, it releases latent heat, which is the heat energy absorbed or released during a phase change at constant temperature. This latent heat is released from the vapor molecules as they transition from the gaseous phase to the liquid phase. Therefore, the correct answer is option (c) "latent". Certainly! "Latent" refers to something that is present but not yet visible, apparent, or actively participating in a process. In the context of heat transfer and phase changes, "latent heat" refers to the heat energy absorbed or released during a phase change at constant temperature. This heat energy does not result in a change in temperature of the substance undergoing the phase change but instead facilitates the transition between different phases of matter. There are two main types of latent heat:

1. Latent Heat of Fusion: This is the heat energy absorbed or released when a substance changes its phase from solid to liquid (melting) or vice versa (freezing) at its melting point. During melting, heat energy is absorbed to break the intermolecular bonds holding the solid structure together, allowing the molecules to transition into a more disordered liquid phase. Conversely, during freezing, heat energy is released as the molecules form stable bonds in the solid phase.
2. Latent Heat of Vaporization: This is the heat energy absorbed or released when a substance changes its phase from liquid to vapor (evaporation) or vice versa (condensation) at its boiling point. During evaporation, heat energy is absorbed to overcome the intermolecular forces holding the liquid molecules together, allowing them to escape into the vapor phase. Conversely, during condensation, heat energy is released as the vapor molecules lose energy and transition back into the liquid phase.

Latent heat plays a crucial role in various natural phenomena and engineering applications. For example, latent heat of vaporization is responsible for the cooling effect of sweat evaporating from the skin, and latent heat of fusion is important in processes such as melting ice to obtain liquid water. In engineering, latent heat is utilized in refrigeration systems, where the phase change of refrigerants facilitates the transfer of heat energy to achieve cooling.