Question

An ice cube melts on the warm sidewalk on a hot summer day. Let the entropies of the ice cube, of the pavement and of the ice cubesidewalk system be Sice, Ssw and Ssys. What happens to these entropies?
1. Sice increases, Ssw decreases, Ssys does not change.
2. Sice decreases, Ssw increases, Ssys decreases
3. Sice increases, Ssw decreases, Ssys increases
4. Sice increases, Ssw increases, Ssys increases

Answer 1

Answer:

3. Sice increases, Ssw decreases, Ssys increases

Explanation:

Entropy basically refers to the degree of disorderliness of a system.

Ice Cube --> As the ice cube melts, it undergoes a change in state of matter from solid to liquid hence it's entropy increases as the degree of movement of its molecules is more disordered in the liquid state.

This means the likely options are; 1, 3 and 4.

Sidewalk --> The entropy here decreases as the ice melts on the side walk. This is because there is a reduction in temperature. Entropy is directly proportional to temperature. Decrease in temperature leads to decrease in entropy.

This means the likely option is 1 and 3

The net entropy change of the system is however positive.