Enthalpy change

Enthalpy change refers to the amount of heat absorbed or released during a chemical or physical process at constant pressure. It indicates whether a process is endothermic (absorbing heat) or exothermic (releasing heat). Think of it as the energy change associated with making or breaking bonds, or transforming substances, without considering work done outside the system. Understanding enthalpy change helps predict how reactions will behave—such as whether they will heat up or cool down—and is vital in fields like chemistry, engineering, and environmental science to manage energy efficiently.