## Change in entropy in a substance

Boltzmann Equation for Entropy: $S = k_{B} \ln W$

harseerat_jajj_3G
Posts: 7
Joined: Wed Sep 28, 2016 3:00 am

### Change in entropy in a substance

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.

Chem_Mod
Posts: 18880
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 714 times

### Re: Change in entropy in a substance

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).

Return to “Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy”

### Who is online

Users browsing this forum: No registered users and 0 guests