K for Gases

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Labiba Sardar 2A
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Joined: Sat Jul 20, 2019 12:15 am

K for Gases

Postby Labiba Sardar 2A » Wed Jan 08, 2020 6:03 pm

When a question asks you to find K for a reaction that involves gases and it doesn't specify whether to find Kc or Kp, should you just find Kp? Or should you put down both Kc and Kp?

nehashetty_2G
Posts: 102
Joined: Thu Jul 25, 2019 12:15 am

Re: K for Gases

Postby nehashetty_2G » Wed Jan 08, 2020 6:08 pm

For a reaction that involves just gases you would use Kp.

AlyshaP_2B
Posts: 112
Joined: Wed Sep 18, 2019 12:19 am

Re: K for Gases

Postby AlyshaP_2B » Wed Jan 08, 2020 6:11 pm

When the reaction is dealing with gases, I believe you should use Kp.

Matthew Tsai 2H
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Joined: Wed Sep 18, 2019 12:20 am

Re: K for Gases

Postby Matthew Tsai 2H » Wed Jan 08, 2020 7:08 pm

For gases you should use Kp, because gases would have a "concentration" in the same way as aqueous solutions, as there is not really a solvent. Instead, the equivalent of concentration for a gas would be its partial pressure.

Dina 2k
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Joined: Wed Sep 18, 2019 12:17 am

Re: K for Gases

Postby Dina 2k » Wed Jan 08, 2020 7:10 pm

Can someone explain 5H.1?

Donna Nguyen 2L
Posts: 100
Joined: Sat Aug 24, 2019 12:17 am

Re: K for Gases

Postby Donna Nguyen 2L » Thu Jan 09, 2020 12:43 am

Dina 2k wrote:Can someone explain 5H.1?

5H.1 is similar to the example shown on page 410 of the textbook, so you can follow that when trying to do this homework problem. In fact, part (a) is almost the same as the example. With the reverse reaction, the equilibrium constant is the reciprocal of the original chemical equation, so it would be 1/(equilibrium constant from original equation).

preyasikumar_2L
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Joined: Fri Aug 09, 2019 12:17 am

Re: K for Gases

Postby preyasikumar_2L » Thu Jan 09, 2020 12:49 am

It probably depends on what you are given in the problem (the partial pressures or the concentrations). You could do either Kp or Kc, as long as you keep track and do not confuse the two because the values will not be the same. And in Wednesday's lecture Lavelle showed us how to convert between Kp and Kc, so either is probably okay.

DHavo_1E
Posts: 118
Joined: Sat Aug 17, 2019 12:17 am

Re: K for Gases

Postby DHavo_1E » Thu Jan 09, 2020 12:47 pm

preyasikumar_2L wrote:It probably depends on what you are given in the problem (the partial pressures or the concentrations). You could do either Kp or Kc, as long as you keep track and do not confuse the two because the values will not be the same. And in Wednesday's lecture Lavelle showed us how to convert between Kp and Kc, so either is probably okay.



Hello,

Could you explain how to convert between Kp and Kc? Thank you!

preyasikumar_2L
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

Re: K for Gases

Postby preyasikumar_2L » Sun Jan 19, 2020 7:22 pm

DHavo_1E wrote:
preyasikumar_2L wrote:It probably depends on what you are given in the problem (the partial pressures or the concentrations). You could do either Kp or Kc, as long as you keep track and do not confuse the two because the values will not be the same. And in Wednesday's lecture Lavelle showed us how to convert between Kp and Kc, so either is probably okay.



Hello,

Could you explain how to convert between Kp and Kc? Thank you!


Kp = Kc(RT)delta n
(R is the 0.08206 Latm/molK constant, T is temperature in Kelvin, delta n is change in moles of gas (gas ONLY) ((products-reactants)) )

RobertXu_2J
Posts: 104
Joined: Fri Aug 30, 2019 12:17 am

Re: K for Gases

Postby RobertXu_2J » Sun Jan 19, 2020 7:53 pm

Find Kp, because the pressure that a gas exerts is used to represent its concentration.

Jesse Anderson-Ramirez 3I
Posts: 54
Joined: Thu Sep 26, 2019 12:18 am

Re: K for Gases

Postby Jesse Anderson-Ramirez 3I » Sun Jan 19, 2020 10:21 pm

You would use Kp because you would use pressure to find the equilibrium constant of gases.

ASetlur_1G
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

Re: K for Gases

Postby ASetlur_1G » Sun Jan 19, 2020 10:46 pm

preyasikumar_2L wrote:
DHavo_1E wrote:
preyasikumar_2L wrote:It probably depends on what you are given in the problem (the partial pressures or the concentrations). You could do either Kp or Kc, as long as you keep track and do not confuse the two because the values will not be the same. And in Wednesday's lecture Lavelle showed us how to convert between Kp and Kc, so either is probably okay.



Hello,

Could you explain how to convert between Kp and Kc? Thank you!


Kp = Kc(RT)delta n
(R is the 0.08206 Latm/molK constant, T is temperature in Kelvin, delta n is change in moles of gas (gas ONLY) ((products-reactants)) )



Do we need to know how to convert between Kp and Kc?

005206171
Posts: 107
Joined: Wed Sep 18, 2019 12:20 am

Re: K for Gases

Postby 005206171 » Sun Jan 19, 2020 11:23 pm

Kp is the specific notation used for gases or when given partial pressures.


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