Which type of reaction is evaporation?

Understanding Evaporation

Have you ever stepped out of a swimming pool on a warm summer day and immediately felt a chill, even though the air is hot? That everyday experience is a great way to understand evaporation, which is classified scientifically as an endothermic process.

To turn a liquid into a gas, molecules need a certain amount of kinetic energy to break free from the liquid's surface and escape into the air as vapor. Because the surrounding environment supplies this necessary thermal energy, the process actually absorbs heat from its immediate surroundings.

This transfer of energy is precisely why evaporation has a cooling effect. When sweat evaporates from your skin, or when water dries off a surface, it pulls heat energy away from you or the object, lowering the temperature. In short, because evaporation requires an input of heat energy to happen, it is fundamentally an endothermic process.