KC vs KP  [ENDORSED]

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Eden Breslauer-Friedman 2A
Posts: 104
Joined: Wed Sep 30, 2020 10:11 pm

KC vs KP

Postby Eden Breslauer-Friedman 2A » Mon Jan 04, 2021 12:00 pm

If we are given a chemical reaction that has gases involved, do we automatically assume we are calculating KP, or does it depend if we are given values in molar concentrations, or atmospheres/bars?

Thanks!

Andrew Wang 1C
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Re: KC vs KP

Postby Andrew Wang 1C » Mon Jan 04, 2021 12:01 pm

It would depend if we are given the values of reactants/products in concentration or bars. I remember some problems in the Audio-Visual modules had us calculate Kc when there were only gases in the reaction.

SahajDole_1C
Posts: 96
Joined: Wed Sep 30, 2020 9:33 pm

Re: KC vs KP

Postby SahajDole_1C » Mon Jan 04, 2021 12:02 pm

Usually the question should mention what to find but it would depend on the values given.

Jonathan Batac - 2D
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Joined: Wed Sep 30, 2020 10:03 pm

Re: KC vs KP

Postby Jonathan Batac - 2D » Mon Jan 04, 2021 12:04 pm

I would always check what units are given. As you stated, if given concentration (Molarity) usually you would be calculating for Kc, and if given atm/bars usually you would be calculating for Kp.

Gabriel Nitro 1E
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Re: KC vs KP

Postby Gabriel Nitro 1E » Mon Jan 04, 2021 12:05 pm

Hi,

It entirely depends on the context on what you are given. If you are given any information which may lead you to find concentrations (), use . If you are given any information which may lead you to find partial pressures (), then use .

Hope this helps! :)

Kareena Patel 1G
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Re: KC vs KP

Postby Kareena Patel 1G » Mon Jan 04, 2021 12:05 pm

If the equation only involves gases, I think it is safe to assume that you should use Kp for the problem.

Kelly Tran 1J
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Re: KC vs KP  [ENDORSED]

Postby Kelly Tran 1J » Mon Jan 04, 2021 10:57 pm

The units will tell you whether you are calculating for Kc or Kp. If the molar concentration is given, you are calculating for Kc. If the units of atm/bar is given, you are calculating for Kp.


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