## Pressure and volume

$PV=nRT$

Deepika Pugalenthi 1A
Posts: 60
Joined: Fri Sep 28, 2018 12:24 am

### Pressure and volume

Are pressure and volume inversely related when identifying the direction a reaction is going to go when changing either factor? For example, if I want to increase the pressure, the reaction would move to the side with fewer moles and vice versa?

Tarika Gujral 1K
Posts: 62
Joined: Fri Sep 28, 2018 12:27 am

### Re: Pressure and volume

Pressure and volume are inversely related, according to Boyle’s law.

Thus increasing pressure implies a decrease in volume.
Decreasing volume causes reaction to move to side with fewer moles of gas.
So increasing pressure causes reaction to move to side with fewer moles of gas.

Faith Fredlund 1H
Posts: 68
Joined: Fri Sep 28, 2018 12:18 am

### Re: Pressure and volume

PV=nRT where P= pressure, V=volume, n= moles, R= gas constant, T=temperature, shows that pressure and volume do indeed have an inverse relationship. Assuming moles, the gas constant, and the temperature do not change (let's call their collective product 1 for simplicity), you now get the equation PV=1 or P=1/V. This shows that they do indeed have an inverse relationship.

michelle
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

### Re: Pressure and volume

Not always. For instance, when the pressure is increased by adding inert gas and the container is not changed, the volume stays the same.

Riley Dean 2D
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

### Re: Pressure and volume

If the pressure is increased by decreasing volume then that is correct but if pressure is increased by pumping gas in then that would be incorrect because moles and volume will have stayed constant and therefore the concentrations will have stayed constant and no change in the reaction will occur