A negative change in entropy indicates that ...

A. the products have a greater number of available energy microstates than the reactants.

B. the products have a smaller number of available energy microstates than the reactants.

Answer: Option (B) is the correct answer.

Explanation:

Entropy is the measure of randomness present within the molecules of a substance.

When entropy of a reaction has a positive sign then it means there is an increase in the entropy. On the other hand, when entropy of a reaction has a negative sign then it means there is a decrease in entropy.

As, entropy change = entropy of products - entropy of reactants

And, larger is the value of entropy more will be the number of microstates.

When entropy is negative then entropy of products is less than the entropy of reactants.

This also means that products have small number of available energy microstates than reactants.

Thus, we can conclude that a negative change in entropy indicates that the products have a smaller number of available energy microstates than the reactants.

B. the products have a smaller number of available energy microstates than the reactants.