k

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Vuong_2F
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Joined: Sat Sep 14, 2019 12:17 am

k

Postby Vuong_2F » Mon Mar 02, 2020 1:40 am

what are the units of k?

605395381
Posts: 50
Joined: Mon Jun 17, 2019 7:24 am

Re: k

Postby 605395381 » Mon Mar 02, 2020 8:02 am

k is unit-less because it is a ration of concentrations of products and reactants

Christineg1G
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Joined: Fri Aug 09, 2019 12:15 am
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Re: k

Postby Christineg1G » Mon Mar 02, 2020 8:35 am

Typically, K doesn't have units since it is a ratio of similar quantities rather than specific concentrations.

AveryAgosto
Posts: 76
Joined: Wed Sep 18, 2019 12:16 am

Re: k

Postby AveryAgosto » Mon Mar 02, 2020 8:49 am

k has no units because it is a ratio

Esha Chawla 2E
Posts: 108
Joined: Thu Jul 25, 2019 12:17 am

Re: k

Postby Esha Chawla 2E » Mon Mar 02, 2020 9:08 am

Vuong_2F wrote:what are the units of k?


K does not have any units.

charleejohnson1L
Posts: 99
Joined: Fri Aug 30, 2019 12:17 am

Re: k

Postby charleejohnson1L » Mon Mar 02, 2020 9:10 am

this has always confused me as well, thank you for asking and thank you to those who answered!
is k the ratio of product concentration to reactant concentration at equilibrium?

ALegala_2I
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

Re: k

Postby ALegala_2I » Mon Mar 02, 2020 10:26 am

Capital K is the equilibrium constant while lower case k is the rate constant for kinetics.

Astrid Lunde 1I
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Joined: Sat Sep 07, 2019 12:16 am

Re: k

Postby Astrid Lunde 1I » Mon Mar 02, 2020 11:59 am

k is the constant rate so it has no units.

Cavalli_1H
Posts: 92
Joined: Thu Sep 19, 2019 12:15 am

Re: k

Postby Cavalli_1H » Mon Mar 02, 2020 12:14 pm

charleejohnson1L wrote:this has always confused me as well, thank you for asking and thank you to those who answered!
is k the ratio of product concentration to reactant concentration at equilibrium?
yes, and because it is a ratio it does not have units

Vuong_2F
Posts: 90
Joined: Sat Sep 14, 2019 12:17 am

Re: k

Postby Vuong_2F » Wed Mar 04, 2020 12:52 am

605395381 wrote:k is unit-less because it is a ration of concentrations of products and reactants

thanks for all the answers everyone but i forgot to clarify in my original question that i'm referring to the k that is in rate laws. i thought that k in the context of kinetics had units?

Labiba Sardar 2A
Posts: 103
Joined: Sat Jul 20, 2019 12:15 am

Re: k

Postby Labiba Sardar 2A » Sun Mar 08, 2020 7:20 pm

Vuong_2F wrote:
605395381 wrote:k is unit-less because it is a ration of concentrations of products and reactants

thanks for all the answers everyone but i forgot to clarify in my original question that i'm referring to the k that is in rate laws. i thought that k in the context of kinetics had units?


In terms of kinetics, the units of k depend on what the order of the reaction is.
If it's 0 order: k = mol.L^-1.s^-1
If it's 1st order: k = s^-1
If it's 2nd order: k = L.mol^-1.s^-1

You can also figure out what the units of k will be by solving for k if you're given the rate, concentrations of the molecules involved in the reaction, and the order of each molecule involved in the reaction.


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