Isothermalisobaric

Isothermalisobaric refers to a thermodynamic process where a system undergoes a change at constant temperature and constant pressure simultaneously. This condition is often encountered in physical and chemical processes that occur in equilibrium with a large reservoir. For example, a phase transition like melting or boiling at a specific temperature and pressure is an isothermalisobaric process. The energy transferred during such a process is primarily the latent heat associated with the phase change, as no work is done due to volume changes at constant pressure if the volume remains constant, or the work done is accounted for by the change in enthalpy.

In an isothermalisobaric process, the system is in thermal contact with a heat bath, ensuring its temperature remains constant. Simultaneously, it is in mechanical contact with a pressure reservoir, maintaining a constant external pressure. While the temperature and pressure are held constant, other thermodynamic variables such as internal energy, entropy, and enthalpy may change. The Gibbs free energy is particularly relevant in isothermalisobaric processes, as it remains constant for spontaneous processes occurring at constant temperature and pressure. This type of process is a common idealization used in thermodynamics and statistical mechanics to simplify calculations and model real-world phenomena.