Question

Obtain a temperature condition for equilibrium.

Answer 1

For a system at equilibrium, free energy change ΔG is,

ΔG = ΔH – TΔS

Where ΔH is enthalpy change, ΔS is entropy change at temperature, T. Since ΔG = 0 at equilibrium,

O = ΔH – TΔS

∴ TΔS = ΔH

OR T = \(\frac{ΔH}{ΔS}\)

Hence at temperature T, 

Changeover between forward spontaneous step and backward non-spontaneous step occurs and the system attains an equilibrium.

Here ΔH and ΔS are assumed to be independent of temperature.