What is enthalpy change (ΔH)?

Enthalpy change (ΔH) is defined specifically as the amount of heat absorbed or released during a process at constant pressure. This concept is crucial in thermodynamics and helps understand how energy is transferred in chemical reactions. When a chemical reaction occurs, it often involves the breaking and forming of bonds, leading to the release or absorption of heat. The measurement of ΔH allows chemists to quantify this thermal energy change and predict whether a reaction is exothermic (releasing heat) or endothermic (absorbing heat).

At constant pressure, the enthalpy change correlates directly with the heat exchange, making it a valuable tool for analyzing the energy dynamics of reactions in various conditions, such as in calorimetry or reaction kinetics.