Question

Which of the following statement regarding entropy is correct?

• A. At absolute zero temperature, the entropy of all crystalline substances is taken to be zero
• B. At 0${}^{\circ }$C, the entropy of all crystalline substances is taken to be zero
• C. At absolute zero temperature,entropy of a perfect crystalline substance is taken to be zero
• D. At 0${}^{\circ }$C, the entropy of a perfect crystalline substance is taken to be zero

Answer 1

Answer: (C)

This is the statement of third law of thermodynamics. In a perfect crystal, at absolute zero temperature, each constituent of lattice must have the lowest energy, so it leads to perfect order, therefore zero entropy.