Pressure in terms of mols

$PV=nRT$

305174946
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

Pressure in terms of mols

Is the pressure lower when there are less mols because they are less collisions? or why?

Brian Chhoy 4I
Posts: 66
Joined: Fri Sep 28, 2018 12:16 am

Re: Pressure in terms of mols

In part, yes. The less moles there are, the less molecules you have colliding with the surface of the container and thus applying less pressure. Also consider the equation PV= nRT, as the number of moles decreases, the pressure has to decrease.

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

Re: Pressure in terms of mols

It depends on how you decrease the pressure. You can either increase the volume or introduce other unrelated gases.You can then relate the change in pressure with the change in moles.

Sophie Roberts 1E
Posts: 61
Joined: Fri Sep 28, 2018 12:17 am

Re: Pressure in terms of mols

Consider pressure in terms of volume as well. When the number of moles stays the same and the volume decreases, the pressure will increase because now there is a more concentrated system. Same vice versa, when the volume increases, the solution is less concentrated so the pressure decreases.