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The entropy of the substance seems to decrease as this substance freezes. Why is this not contradicting the second law of thermodynamics?

User Iman Roosta
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Answer:

See Explanation

Step-by-step explanation:

While it is true that a version of the second law of thermodynamics stated with respect to entropy states that the entropy of a system only increases or remains the same. It never decreases!

It then appears to be a contradiction when the freezing of ice leads to a more ordered structure and a seeming decrease in entropy of the ice as water changes from liquid to solid.

This law of thermodynamics is not violated here because the entropy of the universe increases (freezing is an exothermic process). This outweighs the decrease in entropy of the system hence the change in entropy is positive and the second law of thermodynamics is not violated.

User Pravakar
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