## PV=nRT equation manipulation

$PV=nRT$

Matt Sanruk 2H
Posts: 131
Joined: Wed Sep 18, 2019 12:21 am

### PV=nRT equation manipulation

What was the purpose of changing the equation to equal P or the concentration? Will this be further manipulated when we deal with equilibrium?

Anisha Chandra 1K
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Joined: Thu Jul 11, 2019 12:17 am

### Re: PV=nRT equation manipulation

If you manipulate the equation to solve for P or concentration, then you can use the resulting pressure or concentration in when calculating Kc (concentration) or Kp (pressure).

ELu 1J
Posts: 51
Joined: Thu Jul 25, 2019 12:16 am

### Re: PV=nRT equation manipulation

I think the purpose is just based on the context of the problem. The problem could give the initial concentration of a gas but then ask you to find the partial pressure at equilibrium or something that requires you to be able to convert one to another when the substance is a gas.

Qiu Ya Wu 4I
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Joined: Fri Sep 20, 2019 12:17 am

### Re: PV=nRT equation manipulation

We move elements of the equation around to solve for P and the concentration so we can convert the partial pressure of a gas to its concentration. Being able to do so will be helpful when we deal with heterogenous equilibria.

Callum Guo 1H
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### Re: PV=nRT equation manipulation

You can change the equation around so that you can find the pressure of elements which helps you find the equilibrium for gases

Matt Sanruk 2H
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Joined: Wed Sep 18, 2019 12:21 am

### Re: PV=nRT equation manipulation

Ok I see, but there won't be any problems that give both concentration and pressure for different elements right?

andrewcj 2C
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Joined: Thu Jul 11, 2019 12:17 am

### Re: PV=nRT equation manipulation

If there were, would that be a problem? Assuming the gas constant R was given in the correct units and the temperature was specified, I would think there would be enough information to solve a problem even if both partial pressures and concentrations were part of the information provided.

RobertXu_2J
Posts: 104
Joined: Fri Aug 30, 2019 12:17 am

### Re: PV=nRT equation manipulation

We are manipulating the equation so that we can calculate the value that we want. For example, if we wanted concentration, which is n/V, we would move it to one side and everything else on the other side.

Angela Prince 1J
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Joined: Sat Aug 24, 2019 12:17 am

### Re: PV=nRT equation manipulation

Matt Sanruk 2H wrote:Ok I see, but there won't be any problems that give both concentration and pressure for different elements right?

manipulating the ideal gas law equation gives us a way to convert either partial pressure to concentration or vice versa. so, even if a problem provides values both ways, we should be able to convert them all to the same units.

Matt Sanruk 2H
Posts: 131
Joined: Wed Sep 18, 2019 12:21 am

### Re: PV=nRT equation manipulation

Oh, I see this manipulation can come in handy whenever we are given these circumstances thanks.

Posts: 125
Joined: Sat Aug 17, 2019 12:17 am

### Re: PV=nRT equation manipulation

Matt Sanruk 2H wrote:What was the purpose of changing the equation to equal P or the concentration? Will this be further manipulated when we deal with equilibrium?

The purpose of manipulating PV=nRT is purely to acquire the information that is asked for in the problem, as well as to understand certain concepts. Solving for concentration (n/V) can help understand how changing temperature has on that concentration.

smurphy1D
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### Re: PV=nRT equation manipulation

Is R a constant in every equation? Or does it differ depending on the chemical equation ?

gabbymaraziti
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Joined: Wed Sep 18, 2019 12:19 am

### Re: PV=nRT equation manipulation

Manipulating the PV=nRT is helpful because P gives the partial pressure of gases, which we can use when the problem provides us only with molar concentrations.

Matt Sanruk 2H
Posts: 131
Joined: Wed Sep 18, 2019 12:21 am

### Re: PV=nRT equation manipulation

smurphy1D wrote:Is R a constant in every equation? Or does it differ depending on the chemical equation ?
yes I believe it is a constant but I do not know the number since it is in bar not atm