How does partial pressure affect Gibbs free energy?

1 Answer
Dec 17, 2015

ΔG=ΔG+RTln((PNH3)2(PN2)(PH2)3)

Explanation:

Consider the following reaction:

N2(g)+3H2(g)2NH3(g)

The free energy of this equilibrium could be found by the following expression:

ΔG=ΔG+RTlnK

where K is the equilibrium constant that is given by:

K=(PNH3)2(PN2)(PH2)3

Therefore, the Gibbs free energy is related to the partial pressure by:

ΔG=ΔG+RTln((PNH3)2(PN2)(PH2)3)

Here is a video that explains the origin on this expression in details:

Thermodynamics | Free Energy, Pressure & Equilibrium.