second law statements

Question

According to the Second Law of Thermodynamics, which of the following processes are forbidden?

RankGuru · Accepted Answer

The Second Law of Thermodynamics has multiple equivalent statements that highlight fundamental limits:
1. **Clausius Statement**: Heat cannot spontaneously flow from a colder body to a hotter body without external work.
2. **Kelvin-Planck Statement**: It is impossible to construct a heat engine that operates in a cycle and converts all the heat absorbed from a single reservoir into work.
3. **Entropy Statement**: The total entropy of an isolated system can never decrease over time; it can only stay constant (reversible) or increase (irreversible).
Violation of any of these would violate the Second Law.

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second law statements

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