Thermodynamic process

Definition

A thermodynamic process is a method by which a system changes from one state to another, involving changes in pressure, volume, temperature, or internal energy. These processes are fundamental to understanding the behavior of gases and the application of the First Law of Thermodynamics.

5 Must Know Facts For Your Next Test

1. Thermodynamic processes can be classified as isothermal, adiabatic, isobaric, or isochoric based on which variables are held constant.
2. The First Law of Thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system: $\Delta U = Q - W$.
3. In an isothermal process, temperature remains constant and any heat added to the system does work on the surroundings: $Q = W$.
4. An adiabatic process occurs without transfer of heat or mass between a thermodynamic system and its surroundings: $Q = 0$, so $\Delta U = -W$.
5. In an isochoric process (constant volume), no work is done ($W = 0$), thus any heat added results in a change in internal energy: $\Delta U = Q$.

Review Questions

• What defines an isothermal process in terms of temperature?
• How does the First Law of Thermodynamics apply to an adiabatic process?
• What happens to internal energy during an isochoric process?

Related terms

Isothermal Process: A thermodynamic process where temperature remains constant while pressure and volume may change.

Adiabatic Process: A thermodynamic process with no exchange of heat with its surroundings; all changes occur internally.

Isochoric Process: A thermodynamic process at constant volume with no work done; only heat transfer affects internal energy.