Rate Constant K

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Mike Vinci 2B
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Rate Constant K

Postby Mike Vinci 2B » Sun Mar 04, 2018 5:54 pm

In class, I remember Doctor Lavelle speaking about the units of k, the rate constant, however I wanted to clarify if the units of k can be different depending on the problem we are solving, or if they remain the same across all the problems in the chapter.


Ammar Amjad 1L
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Re: Rate Constant K

Postby Ammar Amjad 1L » Sun Mar 04, 2018 6:02 pm

Units of K change depending on the overall order of the reaction. The units of k change so the concentration x rate constant always yields the same units for the rate. Here is a table from the book.
Screen Shot 2018-03-04 at 5.59.19 PM.png

Sabrina Dunbar 1I
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Re: Rate Constant K

Postby Sabrina Dunbar 1I » Sun Mar 04, 2018 6:05 pm

The units for k change with the different orders of reactions we solve. Homework question 15.9 shows this concept in a question form nicely. Because the units for time and concentration are constant, the units for k must change when we use natural logs versus 1/concentration and so forth.

Katie Blann 1E
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Re: Rate Constant K

Postby Katie Blann 1E » Sun Mar 04, 2018 7:24 pm

He used moles and Molar as examples in the notes.
1st order: 1/s
2nd order: L/molxs or L/Mxs
and so on

Luis De La Cruz 1H
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Re: Rate Constant K

Postby Luis De La Cruz 1H » Sun Mar 04, 2018 9:02 pm

One thing that helps me when trying to figure out the units of K, is the fact that the rate will always end up having to be in (M/s) or Molarity/s, therefore you essentially are manipulating the units of K which as stated above can change depending on the order of the reaction in order to end up with M/S for the rate.

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