At which condition will the entropy of a pure solid be zero? a. when a substance is at absolute zero b. when a substance is undergoing a phase change c. when a substance is in its elemental form d. when the temperature is 0ºc

Option (a) is the correct answer.

Explanation:

The minimum temperature at which there is no heat energy between the molecules of a substance is known as absolute zero.

Absolute zero temperature is also known as zero Kelvin.

Whereas entropy is the measure of randomness. More is the temperature more will be the motion of particles of a substance. Hence, more will be its entropy.

Thus, we can conclude that when a substance is at absolute zero the entropy of a pure solid be zero.