## Clausius inequality

$\Delta S = \frac{q_{rev}}{T}$

Andy Liao 1B
Posts: 52
Joined: Thu Jul 13, 2017 3:00 am

### Clausius inequality

Can someone please explain to me the concept behind the Clausius inequality? The Clausius inequality is ΔS ≥ q/T. Also, what does the statement "with the equality valid for the reversible process" mean?

Gevork 2E
Posts: 32
Joined: Fri Sep 29, 2017 7:05 am
Been upvoted: 1 time

### Re: Clausius inequality

Hi,

From my understanding, the theorem is referencing to the idea that in reality, systems in the world are not completely ideal as we see many times in questions. For instance, work or other factors may be taking part on the system we are looking at, which are going to be altering the value that we get for our entropy. I suppose that it also suggest that such actions always increase entropy as denoted by the great than sign.

So the phrase you list at the end is saying that this equality works for reversible processes which might be suggesting that is won't work for irreversible processes.