Pressure's Effect on Equilibrium

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Charisse Vu 1H
Posts: 101
Joined: Thu Jul 25, 2019 12:17 am

Pressure's Effect on Equilibrium

Postby Charisse Vu 1H » Mon Jan 06, 2020 10:40 pm

Why is it that when pressure is increased by adding an inert gas to a reaction, the K value does not change? Also, what happens when pressure is decreased?

Brian_Ho_2B
Posts: 221
Joined: Fri Aug 09, 2019 12:16 am

Re: Pressure's Effect on Equilibrium

Postby Brian_Ho_2B » Mon Jan 06, 2020 10:51 pm

Inert gases do no side reactions because they're inert. Although they changed the pressure (PV = nRT), they don't change the volume of the container used and thusly the concentrations (n/V) are still the same. This is true for partial pressures as well, since the volume is constant and the moles of gas of the reactants/products are the same. If pressure was changed via changing volume, then values of partial pressures, and concentrations change, and thus reaction quotients (Q) change.

Rita Chen 1B
Posts: 112
Joined: Sat Jul 20, 2019 12:15 am

Re: Pressure's Effect on Equilibrium

Postby Rita Chen 1B » Tue Jan 07, 2020 12:02 pm

I think simply it’s because the inside doesn’t change so the products and reactants don’t change so the K is still the same.

Miriam Villarreal 1J
Posts: 105
Joined: Sat Aug 17, 2019 12:16 am

Re: Pressure's Effect on Equilibrium

Postby Miriam Villarreal 1J » Wed Jan 08, 2020 10:21 pm

Increasing the pressure by adding an inert gas at constant volume has no effect. This is because what matters for the equilibrium are the partial pressures of the reactants and products

Jessica Kwek 4F
Posts: 29
Joined: Mon Jan 06, 2020 7:57 am

Re: Pressure's Effect on Equilibrium

Postby Jessica Kwek 4F » Wed Jan 08, 2020 10:31 pm

The equilibrium constant does not change when pressure is increased by adding an inert gas because it does not react with anything in the reaction. The concentration of each reactant are not changed. The system will still be at equilibrium, which leaves K to remain the same.

Megan Kirschner
Posts: 46
Joined: Wed Feb 20, 2019 12:17 am

Re: Pressure's Effect on Equilibrium

Postby Megan Kirschner » Thu Jan 09, 2020 8:01 pm

What exactly defines an Inert gas? I understand the posts above except for this.

ABombino_2J
Posts: 102
Joined: Thu Jul 11, 2019 12:15 am

Re: Pressure's Effect on Equilibrium

Postby ABombino_2J » Fri Jan 10, 2020 11:08 pm

When an inert gas is added, the concentrations of the products and the reactions are the same because there are the same moles present in the same volume container; therefore, K does not change.


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