(b) If K < 1, then ΔG°=+ve and thus reactions with equilibrium constant K < 1 are thermodynamically spontaneous in reverse direction.
According to thermodynamics the free energy change (ΔG) is equal to the maximum work. In the cell work is done on the surroundings by which electrical energy flows through the external circuit, So
from eq.(i) and (ii) ΔG = –nKEcell
Therefore,partial pressure at new quilibrium are :
Solving, T = 429.7K