Justify the following statements: (i) Reactions with ΔG^0 < 0 always have an equilibrium constant greater than 1.
Justify the following statements:
(i) Reactions with ΔG0 < 0 always have an equilibrium constant greater than 1.
(ii) Many thermodynamically feasible reactions do not occur under ordinary conditions.
(iii) At low temperatures, enthalpy change dominates the ΔG expression and at high temperatures, it is the entropy which dominates the value of ΔG.
1 Answers
(i) –ΔG0 = RT ln K. Thus, if ΔG0 is less than zero, i.e., it is –ve, then ln K will be +ve and hence K will be greater than 1.
(ii) Under ordinary conditions, the average energy of the reactants may be less than threshold energy. They require some activation energy to initiate the reaction.
(iii) ΔG = ΔH – TΔS. At low temperature, TΔS is small .Hence, ΔH dominates. At high temperatures, TΔS is large, i.e. , ΔS dominates the value of ΔG.