What type of reaction occurs when breaking molecules apart to overcome intermolecular forces?

When breaking molecules apart to overcome intermolecular forces, the reaction is classified as endothermic. This is because energy must be absorbed from the surroundings to overcome the attractive forces that hold the molecules together. Intermolecular forces, such as hydrogen bonds, dipole-dipole interactions, and London dispersion forces, contribute to the stability of the molecular structure. To separate these molecules, additional energy is needed to weaken or overcome these forces—hence, the need for an endothermic process.

In endothermic reactions, the overall energy of the system increases because energy is taken in. As this energy is supplied (often in the form of heat), it allows for the molecular bonds or intermolecular forces to break, leading to a change in state (such as melting or vaporization) or dissociation in a chemical reaction. This is in contrast to exothermic reactions, which release energy when bonds are formed, generally leading to more stable products.