(a) ∆G=∆G∘ 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, ∆G=0. (c) ∆G measures spontaneity of a reaction. (d) When ∆G>0, thereaction will proceed in backward direction.