Kc vs Kp

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Bijan Mehdizadeh 1B
Posts: 73
Joined: Fri Sep 28, 2018 12:15 am

Kc vs Kp

Postby Bijan Mehdizadeh 1B » Tue Jan 08, 2019 10:00 am

If we are asked to find K, do we assume it is Kc or Kp?

Reva Kakaria 1J
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am
Been upvoted: 1 time

Re: Kc vs Kp

Postby Reva Kakaria 1J » Tue Jan 08, 2019 10:26 am

I believe it depends on what you are given: if you are given the concentrations of the molecules in the chemical reaction, then it's Kc, and if you are given the partial pressures, you have to find Kp.

Fanny Lee 2K
Posts: 73
Joined: Fri Sep 28, 2018 12:29 am

Re: Kc vs Kp

Postby Fanny Lee 2K » Tue Jan 08, 2019 11:20 am

When you're given both units of concentration and units of pressure in an equilibrium equation, you must convert the units of pressure into units of concentration using the ideal gas law.

Brian Hom 2F
Posts: 60
Joined: Fri Sep 28, 2018 12:24 am

Re: Kc vs Kp

Postby Brian Hom 2F » Tue Jan 08, 2019 1:34 pm

It just depends on what the problem gives you and what it is asking for. If we need to find partial pressures we are dealing with Kp but if we need to find concentrations we are dealing with Kc.

Adrian C 1D
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

Re: Kc vs Kp

Postby Adrian C 1D » Tue Jan 08, 2019 4:04 pm

It important also to take note of the states of the reactants and products. For example, if you have only gases you are probably using partial pressures and therefore Kp.


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