## Units for pressure

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

Ashley Kenney 1E
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Joined: Wed Nov 14, 2018 12:23 am

### Units for pressure

When calculating work, does it matter what unit of pressure is being used? Or should we convert whatever unit of pressure we are given to atmospheres?

Ronald Thompson 1F
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Joined: Fri Sep 28, 2018 12:25 am

### Re: Units for pressure

For a final answer I believe you want to use atm unless otherwise stated. You might have to do some conversions (Torr to atm)

Lasya Gudipudi 1A
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### Re: Units for pressure

To play it safe, I would just convert to atmospheres anytime you are asked for pressure.

SydBenedict2H
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Joined: Wed Nov 08, 2017 3:00 am

### Re: Units for pressure

If its ever in bar, thats more or less equivalent to atm.

MichaelMoreno2G
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Joined: Fri Sep 28, 2018 12:26 am

### Re: Units for pressure

SydBenedict2H wrote:If its ever in bar, thats more or less equivalent to atm.

Exactly, I remember the professor saying the difference between bar and atm is very small.

kateminden
Posts: 63
Joined: Fri Sep 28, 2018 12:24 am

### Re: Units for pressure

Yeah, I believe generally we would use atm unless a different unit was given in a specific problem.

405021651
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Joined: Tue Nov 14, 2017 3:03 am

### Re: Units for pressure

Usually atm is used!

Mercan Bayazit 4E
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Joined: Fri Sep 28, 2018 12:20 am

### Re: Units for pressure

Yes, I think we generally use atm for pressure, even though the difference is small.

505211599
Posts: 60
Joined: Fri Sep 28, 2018 12:28 am

### Re: Units for pressure

You would normally use atm or bar as units in your answer.

Nicolle Fernandez 1E
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Been upvoted: 1 time

### Re: Units for pressure

You would preferably use atm but using bar is okay bc the difference between atm and bar is so small

005115864
Posts: 64
Joined: Fri Sep 28, 2018 12:15 am

### Re: Units for pressure

Refer to the constants and go from there. If the problem gives you torr, and whatever constant you're using uses atm, then make sure to use atm in order to be able to cancel them out properly.