Pressure, Volume

Moderators: Chem_Mod, Chem_Admin

Siddiq 1E
Posts: 106
Joined: Fri Aug 09, 2019 12:15 am

Pressure, Volume

Postby Siddiq 1E » Fri Mar 13, 2020 1:24 pm

Can someone explain the relationship between pressure, volume, and le chatelier? Like what if both sides of the equation have equal numbers of moles, how will a pressure change affect that?

Diana A 2L
Posts: 106
Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

Re: Pressure, Volume

Postby Diana A 2L » Fri Mar 13, 2020 1:31 pm

Siddiq 1E wrote:Can someone explain the relationship between pressure, volume, and le chatelier? Like what if both sides of the equation have equal numbers of moles, how will a pressure change affect that?


So if the number of moles is the same, a pressure change won’t affect the equilibrium. Since the pressure will change for the entire system, and both sides have equal moles, the change in volume will be consistent for the both reactants and products side.

Siddiq 1E
Posts: 106
Joined: Fri Aug 09, 2019 12:15 am

Re: Pressure, Volume

Postby Siddiq 1E » Fri Mar 13, 2020 1:34 pm

Sorry I meant a pressure change for one of the reactants or products.

Diana A 2L
Posts: 106
Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

Re: Pressure, Volume

Postby Diana A 2L » Fri Mar 13, 2020 2:08 pm

Siddiq 1E wrote:Sorry I meant a pressure change for one of the reactants or products.


I can’t think of any case in which this will happen. In order to change the pressure for a SPECIFIC reactant or product without changing the pressure of the whole system, that reactant or product would have to be isolated. And in that case, you wouldn’t have equilibrium because there would be no reaction at all. You can only change the pressure of a system not its specific reactants or products.

ramiro_romero
Posts: 90
Joined: Sat Sep 07, 2019 12:16 am

Re: Pressure, Volume

Postby ramiro_romero » Fri Mar 13, 2020 7:10 pm

well we know the ideal gas law inversely relates pressure with volume, pv=nRT, meaning as one increases the other decreases.
Last edited by ramiro_romero on Sat Mar 14, 2020 7:00 pm, edited 1 time in total.

Diana A 2L
Posts: 106
Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

Re: Pressure, Volume

Postby Diana A 2L » Fri Mar 13, 2020 7:15 pm

ramiro_romero wrote:well we know the ideal gas law inversely relates pressure with volume, pv=nRT, meaning as one increases the other decreases. I haven't seen it being related to le chateliers principle however.


Pressure is literally directly related to Le chateliers. Just like a change in volume or concentration affects equilibrium, changes in pressure do too. For example, if you have a reaction with 3 moles of reactant and 2 moles of product in equilibrium, an increase in pressure will shift the equilibrium to the product side because there are less moles of a gas.


Return to “Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions”

Who is online

Users browsing this forum: No registered users and 1 guest