## Kc vs Kp

$PV=nRT$

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### Re: Kc vs Kp

When you are given the concentration of the reactants and products, you use Kc. However, if you are given the partial pressures of the reactants and products, you would use Kp.

Gustavo_Chavez_1K
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### Re: Kc vs Kp

Kc is used when the concentrations of reactants and products are given for a solution. Kp is used when the partial pressure is given for a gas.

Anthony_Sandoval_1D
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### Re: Kc vs Kp

Kc is used for concentration where Kp is used specifically for partial pressure.

RyanKopeikin_2I
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Joined: Fri Aug 30, 2019 12:17 am

### Re: Kc vs Kp

Kp = equilibrium constant using the equilibrium partial pressures for the reactants & products.
Kc = equilibrium constant using the equilibrium molar concentrations for the reactants & products.

Emerald Wong 1B
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### Re: Kc vs Kp

Rachel Kho Disc 2G wrote:Also will we need to have the formula that converts Kc to Kp memorized? Or will that be given to us on an equations sheet?

The ideal gas law that converts concentration to pressure is easy to memorize! I'm not sure if that was what you were asking in terms of converting Kc to Kp.

Lorraine Medina 3E
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### Re: Kc vs Kp

Kc is used for concentrations while Kp is used for partial pressures. Hope this helps!

Akriti Ratti 1H
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### Re: Kc vs Kp

Kc is for concentration, while Kp is for partial pressure.

Nancy Yao
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Joined: Wed Sep 30, 2020 9:38 pm

### Re: Kc vs Kp

Rachel Kho Disc 2G wrote:Also will we need to have the formula that converts Kc to Kp memorized? Or will that be given to us on an equations sheet?

Isn't that equation is PV=nRT?

Nina Fukui 2J
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### Re: Kc vs Kp

Kp is used when partial pressures are given and Kc is used when concentrations are given but they both are equilibrium constants!

Nan_Guan_1L
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Joined: Wed Sep 30, 2020 9:59 pm

### Re: Kc vs Kp

just to add on to the discussion above,
it also depends on what is given to you. if the question gave you conditions in barr or atm, then go for Kp. if the question gave you concentration, then go for Kc.