Change in entropy in a substance

Boltzmann Equation for Entropy:

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Change in entropy in a substance

Postby harseerat_jajj_3G » Sun Jan 22, 2017 7:01 pm

I was reading through the book and I did not fully understand the concepts behind the change in entropy in a substance going through one phase to another. I did not understand one of the three facts: how is the transfer of heat is reversible at the temperature of a phase transition? Thanks.

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Re: Change in entropy in a substance

Postby Chem_Mod » Mon Jan 30, 2017 9:52 pm

Hey Harseerat! A good way of looking at it is through the heat put in or taken out of the system. If I am changing from a solid to a liquid, I have to put in a certain amount of heat. If I go from a liquid to a solid, I need to take out the exact same amount of heat. The amount of heat does not change depending on the direction I am going( liquid to solid or solid to liquid).

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