Chapter 20, Problem 18TE

What role does entropy play in chemical reactions?

To determine

The role of entropy in a chemical reaction.

Answer to Problem 18TE

Entropy indicates the spontaneity of a reaction.

Explanation of Solution

The term entropy of a system states the randomness of a molecule in a system or the disorderness of a system. Entropy is the thermodynamic parameter that is used to determine whether the chemical reaction is spontaneous or not.

If the overall entropy of a system is increasing from the reactant to the product molecule in a chemical reaction, then it is a spontaneous reaction.

If the overall entropy of a system is decreasing from the reactant to the product molecule in a chemical reaction, then it is a non-spontaneous reaction.

Entropy also indicates whether the Gibbs free energy is increasing or not.

If the entropy of a system is negative that means it is losing its free energy thus leading to spontaneous reaction and vice-versa.

Conclusion:

Therefore, entropy indicates the spontaneity of a reaction.