Consider the following reaction: N2(g) + 3H2(g) ↔ 2NH3(g) ΔH = - 92.4 kJmol -1

a) The absolute entropy values, S, at 238 K for N2(g), H2(g) and NH3(g) are 192, 131 and 193 J K -1mol -1respectively. Calculate ∆Sº for the reaction and explain the sign of ∆Sº.

b) Calculate ∆Gº for the reaction at 238 K. State and explain whether the reaction is thermodynamically favored.