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### Free Expansion

Posted: Mon Feb 12, 2018 2:45 pm
Are the values of Free Expansion the same as the values for an Isolated System in terms of deltaU, w, q, and deltaH?

All would be equal to zero?

Are free expansion and isolated system synonymous?

### Re: Free Expansion

Posted: Mon Feb 12, 2018 5:04 pm
They are conceptually a little different but yes, I think the variables you listed would all be zero for both.

### Re: Free Expansion

Posted: Mon Feb 12, 2018 5:40 pm
There is no work down on a free expansion. When you are looking at an isothermal free expansion, you know that delta U= 0.
So that means -w=q.
We just said that there is no work done on a free expansion, so both q & w would equal 0. Thus no heat transferred into the surroundings, so the entropy is unchanged. So the delta S= delta S tot

### Re: Free Expansion

Posted: Mon Feb 12, 2018 5:41 pm
^^ that is in an irreversible isothermal free expansion

### Re: Free Expansion

Posted: Mon Feb 12, 2018 5:44 pm
In an isothermal, reversible free expansion, delta S tot= 0 because it is an equilibrium.
So, delta S sys= -delta S surr