Question

Which of the following statements regarding entropy is correct? 

(a) At absolute zero temperature, the entropy of all crystalline substances is taken to be zero. 

(b) At 0°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°C, the entropy of a perfect crystalline substance is taken to be zero

Answer 1

Correct option (c) At absolute zero temperature,entropy of a perfect crystalline substance is taken to be zero. 

Explanation:

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.