👉 The term "enthalpy" is defined as a measure of the heat energy that a substance can absorb or emit when it undergoes a chemical reaction. It is denoted by H and is a scalar quantity, meaning its value does not depend on the specific state of the substance involved in the reaction. In thermodynamics, enthalpy plays an essential role in understanding the behavior of substances and their interactions with each other at various temperatures. The enthalpy change (ΔH) for a chemical