Explanation:

Entropy is a measure of the disorder of a system. When a liquid is converted to a solid, the molecules become more ordered. This decrease in disorder results in a negative entropy change.

The molecules in a liquid are free to move around more than the molecules in a solid. As a result, there is more disorder in a liquid than in a solid. When a liquid is converted to a solid, the molecules lose their freedom to move around as much. This results in a decrease in disorder, or a negative entropy change.