What type of process is vaporization in terms of enthalpy?

Vaporization is considered an endothermic process because it requires the absorption of heat in order to convert a substance from its liquid phase to its gaseous phase. During vaporization, energy is needed to overcome the intermolecular forces that hold the molecules together in the liquid state. As heat is absorbed, these molecules gain kinetic energy, allowing them to escape the liquid and become vapor.

Additionally, when a substance vaporizes, the temperature of the remaining liquid can decrease, as the heat energy is being drawn from it. This energy transfer is a hallmark of endothermic processes, where the system takes in energy. Thus, the classification of vaporization as an endothermic process is due to the heat input required for the transition from liquid to gas.

This understanding is essential in thermodynamics and physical chemistry, where the concepts of heat transfer and phase changes play a vital role in various reactions and processes.