(a) ΔG=ΔG∘ for a standard system of STP condition (25∘C,1atm) The corrected statements of options-(a), (c) and (d) will be like, (b) At equilibrium state, ΔG=0. (c) ΔG measures spontaneity of a reaction. (d) When ΔG>0, thereaction will proceed in backward direction.