Question

The absolute entropy for all crystalline substances at absolute zero temperature is

• A. Zero
• B. Negative
• C. Positive
• D. Indeterminate

Hint:

Third law of thermodynamics states that entropy of a perfect crystal at \(0\text{ K}\) is zero.

Answer 1

The Correct Option is A

This question is based on the third law of thermodynamics. According to the third law of thermodynamics, the entropy of a perfect crystalline substance at absolute zero temperature is zero. Absolute zero temperature is: \[ 0\text{ K} \] At absolute zero, a perfect crystal has only one possible arrangement of particles. Therefore, randomness becomes minimum. Since entropy is a measure of randomness, the entropy becomes zero. Thus: \[ S=0\quad \text{at}\quad T=0\text{ K} \] Therefore, the absolute entropy for all perfectly crystalline substances at absolute zero is: \[ \text{Zero} \]