Question
(i) What are the limitations of criterion for randomness?
(ii) Calculate the standard free energy of formation of 
The free change for the reaction.
Solution
(i) Processes like solidification of a liquid and liquefaction of a gas are accompanied by a decrease in randomness (entropy). If randomness factor were the only criterion of the spontaneity of a reaction, then these processes would not have been feasible. In other words, the tendency to acquire maximum randomness (entropy) is a factor which determines the spontaneity of a reaction, but it is not the sole criterion.
(ii) We know that,
Substituting the values, we have,
(ii) We know that,
Substituting the values, we have,
