Practice question · Multiple choice
Why does a perfect crystal at absolute zero have exactly zero entropy?
Hints
- Use the statistical definition and count the arrangements.
- A perfect crystal at 0 K has W = 1, and ln 1 = 0.
Show the answer
B. There is only one way to arrange it, and the logarithm of one is zero
Why
With every atom fixed in a unique arrangement, and . This is the third law, and it is what gives entropy genuine absolute values where enthalpy has only differences.
Practise Entropy and the Second Law
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