Comment on the following statements:
(a) An exothermic reaction is always thermodynamically spontaneous.
(b) Reaction with `DeltaG^(@) lt 0` always have an equilibrium constant greater than 1.

Explanation

(a) Exothermic reactions are generally spontaneous because
(i) these are accompained by decrease of energy
(ii) the heat released is absorbed by the surroundings so that entropy of the surroundings increases and therefore, `DeltaS_("total")` is positive. However, if `DeltaS` system is -ve and T is very high, `DeltaG(DeltaG = DeltaH -TDeltaS)` may be positive and the reaction may be non - spontaneous.
(b) `DeltaG lt 0` shows that the process is spontaneous.Equilibrium constant may not have value `gt 1 (DeltaG^(@) = -RTIn K)`.