Gibbs Free Energy

Gibbs free energy is equal to the enthalpy of the system less the product of the temperature and entropy.
The equation is given as:

Where,
G = Gibbs free energy
H = enthalpy
T = temperature
S = entropy
OR or a more complete equation would be given as:

Where,
U = internal energy (SI unit: joule)
P = pressure (SI unit: pascal)
V = volume (SI unit: m3 )
T = temperature (SI unit: kelvin)
S = entropy (SI unit: joule/kelvin)

Gibbs free energy is also connected to the transformation in the overall entropy of the universe during a particular process at a given temperature. Precisely, the equation is as follows: ΔG = -TΔSuniv, where T denotes temperature, and ΔSuniv signifies the modification in the universe's entropy.