Question

When a solid melts reversibly
[H-Enthalpy, G-Gibbs Free energy, E- internal energy, S- Entropy]

• A. H decreases
• B. G increases
• C. E decreases
• D. S increases

Answer 1

Answer: (D)

S increases

A solid needs to absorb some energy to melt. H is positive and G remains unchanged. The structure of a solid is usually well ordered, the structure of a liquid is less ordered, and that of gas is quite random. Thus, liquid has more entropy than solids. Entropy, S increases when solid melts.

Hence, option D is correct.