Delta g stands for change in Gibbs Free Energy.

Gibbs free energy is the maximum amount of non-expansion work that can be extracted from a thermodynamically closed system.

ΔG determines the direction and extent of chemical change.

**Formula to calculate delta g.**

ΔG is change in Gibbs free energy.

ΔH is change in enthalpy.

T is temperature in Kelvin.

ΔS is change in entropy.

**Example:**

If the change in enthalpy is 646 J and the temperature is 200K, calculate the Gibbs free energy if the change in entropy is 50 JK−1mol−1.

Therefore, the Gibbs free energy is -9,354 joules.