Which of Energy, Work, Enthalpy and Heat Are State Functions?

Enthalpy and energy are state functions; work and heat are not state functions. A state function in thermodynamics is a property of a system that only depends on the initial state and the final state. Due to this, state functions are considered to be path-independent.

A state function measures an equilibrium state in a thermodynamic system. Since state functions are path-independent, they can be used to describe the parameters of a thermodynamic system and its equilibrium values. Other state functions include pressure, temperature, volume and mass.

In contrast, work and heat are process quantities because their values and properties are path-dependent.