## Isolated System

$w=-P\Delta V$
and
$w=-\int_{V_{1}}^{V_{2}}PdV=-nRTln\frac{V_{2}}{V_{1}}$

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Emily Glaser 1F
Posts: 156
Joined: Thu Jul 27, 2017 3:01 am

### Isolated System

Is

delta U=0
q=0
w=0
delta H=0

in an isolated system?

Salman Azfar 1K
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

### Re: Isolated System

An isolated system means no energy or matter can flow in or out, so often that will be the case. So yea, in isolated systems w and q will both be zero and delta U is zero.

Ramya Lakkaraju 1B
Posts: 67
Joined: Fri Sep 29, 2017 7:03 am

### Re: Isolated System

This fact that delta U = 0 allows us to set q = -w and do other calculations involving heat and work.

CalebBurns3L
Posts: 47
Joined: Fri Sep 29, 2017 7:07 am

### Re: Isolated System

Yes, since no energy or matter would be flowing in or out with all of those values set to 0.

Kevin Tabibian 1A
Posts: 42
Joined: Fri Sep 29, 2017 7:06 am

### Re: Isolated System

Yes, but be careful determining whether a question is asking for the change in energy of the system or a reaction within the system. Because all those terms could very well not be equal to zero for to a reaction within an ideal bomb calorimeter. But the total energy of the bomb calorimeter will be unchanged.

204932558
Posts: 23
Joined: Fri Sep 29, 2017 7:05 am

### Re: Isolated System

Yes, as no heat or matter flows into the system or exits the system.

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