How does partial pressure affect Gibbs free energy?
1 Answer
If you increase the partial pressure of a product gas,
The equation for Gibbs free energy is
For a gas phase reaction of the type
aA(g) + bB(g) ⇌ cC(g) + dD(g),
This shows that if you increase the partial pressure of a product gas,
If you increase the partial pressure of a reactant gas,
EXAMPLE
For the reaction
2A(g) + 2B(g) ⇌ C(g) + 3D(g)
at 25 °C, the equilibrium partial pressures are
At equilibrium,
-8.314 J·K⁻¹mol⁻¹ × 298 K ×
-2478 J·K⁻¹mol⁻¹ × ln2.34 = -2110 J/mol = -2.11 kJ/mol