Enthalpy

Enthalpy is a measure of the total energy in a system, combining its internal energy with the energy required to make space for it in its surroundings (pressure and volume). In equilibrium thermodynamics, it helps us understand how energy is transferred during processes like heating or chemical reactions while keeping pressure constant. Changes in enthalpy can indicate whether a reaction absorbs or releases heat, which is crucial for predicting how systems will behave under different conditions. Essentially, it's a key concept for understanding energy flow in various physical and chemical processes.