alleryStart learning →Melting is described as spontaneous at 10.00 degrees Celsius because at that temperature:
ASystem mass rises
BSystem mass falls
CUniverse entropy rises
DUniverse entropy falls
Answer & Solution
Correct answer: C. Universe entropy rises
1. Spontaneity is judged by the entropy change of the universe.
2. At 10.00 degrees Celsius the entropy change of the universe is greater than zero.
3. So melting is spontaneous at 10.00 degrees Celsius.
4. At minus 10.00 degrees Celsius that change is negative and melting is nonspontaneous.
_Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 16 'Thermodynamics', sections 16.1-16.4_
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