k values

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Samantha Chung 4I
Posts: 77
Joined: Wed Oct 03, 2018 12:16 am

k values

Postby Samantha Chung 4I » Tue Mar 05, 2019 10:07 pm

I do not quite grasp the concept of "k" how do we determine the units of k, does k even have units?

Searra Harding 4I
Posts: 68
Joined: Fri Sep 28, 2018 12:29 am

Re: k values

Postby Searra Harding 4I » Tue Mar 05, 2019 10:59 pm

k is a rate constant and commonly seen as a proportionality constant. You can determine units by plugging in your rates to the rate expression and raising them to the respective exponent (rates are in M/s which is the same as mol/(L*s)). So if k= rate/([A]^2[B]) then k will have the units M^-2 s^-1.

Philipp_V_Dis1K
Posts: 32
Joined: Fri Sep 28, 2018 12:20 am

Re: k values

Postby Philipp_V_Dis1K » Wed Mar 06, 2019 9:33 am

K depends on the order of the reaction, because the concentrations of the reactants are raised to different powers.

Danny Elias Dis 1E
Posts: 60
Joined: Fri Sep 28, 2018 12:19 am

Re: k values

Postby Danny Elias Dis 1E » Fri Mar 08, 2019 9:41 am

Is k only found experimentally (like order), or do we have to calculate k given reactant concentrations and a rate law?

Eric Quach 1C
Posts: 30
Joined: Fri Sep 28, 2018 12:20 am

Re: k values

Postby Eric Quach 1C » Fri Mar 08, 2019 8:18 pm

k is the rate constant and is different for each reaction. the units for k vary depending on the order of the reaction. k can be found experimentally, but on the tests we will probably have to calculate it or solve for it.


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