## kc vs kp

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jane_ni_2d
Posts: 67
Joined: Fri Sep 28, 2018 12:23 am

### kc vs kp

can kp also be used in place of kc?

Cynthia Ulloa
Posts: 52
Joined: Fri Feb 23, 2018 3:02 am

### Re: kc vs kp

Kp is specific to the equilibrium constant for partial pressures of gases while Kc is used for molar concentrations such as when working with aqueous elements.

Ethan Yi 1K
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Joined: Fri Sep 28, 2018 12:28 am

### Re: kc vs kp

Kp is p for partial pressures (gases) and Kc is c for concentration

Saman Andalib 1H
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Joined: Fri Sep 28, 2018 12:16 am

### Re: kc vs kp

If you are referring to its use in an ICE table, Kp can only be used when all of the values in the molecules represented in the equilibrium expression for that particular chemical equation are in the gas phase.

Posts: 57
Joined: Fri Sep 28, 2018 12:27 am

### Re: kc vs kp

Conceptually they are different, for Kp is utilised for partial pressure and Kc for concentration. However, solving them is the same method.

Posts: 64
Joined: Fri Sep 28, 2018 12:26 am

### Re: kc vs kp

Kp cannot be used in place for Kc, but you can convert one into the other by using the formula: Kp= Kc(RT)^delta n. Delta n is equal to the moles of the products minus the moles of the reactants. This formula relates Kp to Kc, so you can convert one to the other.

Chris Dis3L
Posts: 45
Joined: Fri Sep 28, 2018 12:25 am

### Re: kc vs kp

Kc and Kp are different. Kc is defined by molar concentrations, whereas Kp is defined by the partial pressure of the gasses inside a closed system. However, you can convert between the two with the following equation: Kp = Kc(RT)^Δn.

IsabelLight2H
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Joined: Wed Oct 03, 2018 12:15 am

### Re: kc vs kp

If they just say "k" do we assume Kp? Because in one problem in the textbook they used K and then it was Kc.

vaishali 1D
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Joined: Fri Sep 28, 2018 12:19 am

### Re: kc vs kp

Kp is for pressure, whereas Kc is for concentration. When writing out the formula for Kp, you must say the partial pressure of the compound (for example, P subscript O2). For Kc, you don't use the large P, you simply put it in brackets to indicate concentration.

Danny Zhang 4L
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Joined: Fri Sep 28, 2018 12:26 am

### Re: kc vs kp

You can really only use kc in place of kp when all of the compounds involved in the reaction are in the gaseous phase.

Eruchi Okpara 2E
Posts: 53
Joined: Fri Sep 28, 2018 12:28 am

### Re: kc vs kp

IsabelLight2H wrote:If they just say "k" do we assume Kp? Because in one problem in the textbook they used K and then it was Kc.

I think you can assume Kp when both reactants and products are all in the gas phase, or if told to find the equilibrium constant in atm. But I think that it might be safe to simply assume that K just means Kc if not given any other specific information.

Diana Sandoval 1K
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Been upvoted: 1 time

### Re: kc vs kp

You can use them interchangeably, difference is that Kc is used for concentration while Kp is used for pressure.

abbydouglas1K
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Joined: Fri Sep 28, 2018 12:26 am

### Re: kc vs kp

Kc and Kp are interchangeable they just denote different measuring methods!

Posts: 38
Joined: Fri Sep 28, 2018 12:22 am

### Re: kc vs kp

They both are found and used using the same methods but Kc is used for concentration and Kp is used for pressures of gasses

JacobHershenhouse3G
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Joined: Thu Jan 10, 2019 12:17 am

### Re: kc vs kp

Kc and Kp are not interchangeable. Kc is found and can only be used in relation to concentrations and Kp is related to the partial pressures of products and reactants. Hope this helps!

Zubair Ahmed 1L
Posts: 81
Joined: Fri Sep 28, 2018 12:16 am

### Re: kc vs kp

Kc and Kp do not represent the same thing. Kp refers to the equilibrium constant using partial pressures while Kc refers to the equilibrium constant using concentration values.

jocelyntzeng
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

### Re: kc vs kp

they are used interchangeably just depends on what you are given, partial pressures or concentrations