pv=nrt

$PV=nRT$

Leslie Almaraz 4G
Posts: 99
Joined: Fri Aug 02, 2019 12:16 am

pv=nrt

Can there be a change indicated to p, v, r, and t depending on the question?

kim 2I
Posts: 105
Joined: Thu Jul 25, 2019 12:17 am

Re: pv=nrt

R is Rydberg's constant so it can't have a change, but volume (V) and moles (n) can have a change since when the moles of gas changes, the volume changes as well.

Michelle N - 2C
Posts: 117
Joined: Wed Sep 18, 2019 12:19 am

Re: pv=nrt

Kind of like what the previous person said, R is a gas constant, so that can't really be changed (given on our equations sheet). For everything else though, yes there could be change. That's also where the mini-questions during lectures are formed "What would happen to ____ if ____ increased?" Hope this helps!

Posts: 107
Joined: Sat Aug 17, 2019 12:16 am
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Re: pv=nrt

Michelle N - 2C wrote:Kind of like what the previous person said, R is a gas constant, so that can't really be changed (given on our equations sheet). For everything else though, yes there could be change. That's also where the mini-questions during lectures are formed "What would happen to ____ if ____ increased?" Hope this helps!

How does a change in pressure affect the other variables: v, n, r, and t?

Jasmine Kim 1L
Posts: 71
Joined: Fri Aug 02, 2019 12:16 am

Re: pv=nrt

Kayla Maldonado 1A wrote:How does a change in pressure affect the other variables: v, n, r, and t?

A change in pressure can be caused by a change in V, n, or T. R is never changed.
An increase in pressure could be caused by: a decrease in volume, an increase in number of moles, or an increase in temperature.
A decrease in pressure could be caused by: an increase in volume, a decrease in the number of moles, or a decrease in temperature.

Jasmine Kim 1L
Posts: 71
Joined: Fri Aug 02, 2019 12:16 am

Re: pv=nrt

Kayla Maldonado 1A wrote:How does a change in pressure affect the other variables: v, n, r, and t?

It's easier if you just look at the equation PV = nRT. If pressure changes, volume changes in the opposite direction because it is multiplied with P and it needs to make up for the change. However, n and T change in the same direction because they are trying to stay equal with PV.

AronCainBayot2K
Posts: 101
Joined: Fri Aug 30, 2019 12:17 am

Re: pv=nrt

Pressure, volume, moles, and temperature can all vary as R is is the Ideal gas law constant. Usually, there are relationships such as when volume increases, pressure decreases, while temperature and moles carry a similar relationship.

Naneeta Desar 1K
Posts: 106
Joined: Fri Aug 09, 2019 12:15 am

Re: pv=nrt

Yes, p,v,n, and t are all variable while r is constant. It just depends on what information the question provides for you.

Veronica Lu 2H
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Joined: Wed Sep 18, 2019 12:18 am
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Re: pv=nrt

everything in the equation except for R is variable. R is a constant and you can use that accordingly with the information given in the problem

KBELTRAMI_1E
Posts: 108
Joined: Sat Jul 20, 2019 12:17 am

Re: pv=nrt

How many variables would we have to be given? All but one? Or are there cases where we are only given two or three variables and we are supposed to find the remaining two? If so, what chemistry knowledge would allow for this, since traditionally in algebra we are seeking the value for a single variable.