How to determine the order of a reactant

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Ellen Amico 2L
Posts: 101
Joined: Thu Sep 19, 2019 12:16 am

How to determine the order of a reactant

Postby Ellen Amico 2L » Sun Mar 08, 2020 7:18 pm

How do you determine the order of a species in a reaction from experimental data when there's no experiment where only the concentration of that species is changing?

SnehinRajkumar1L
Posts: 101
Joined: Thu Jul 11, 2019 12:15 am

Re: How to determine the order of a reactant

Postby SnehinRajkumar1L » Sun Mar 08, 2020 8:06 pm

You can still solve it using the same method. However, you would most likely need to know the order of the other species to solve for it or would need more algebra to go through the problem.

Wilson 2E
Posts: 100
Joined: Sat Aug 17, 2019 12:18 am

Re: How to determine the order of a reactant

Postby Wilson 2E » Sun Mar 08, 2020 8:09 pm

Within the scope of this class at least, you can only calculate the order of a species when it is the only concentration changing.

Juliet Stephenson 4E
Posts: 100
Joined: Wed Sep 18, 2019 12:21 am

Re: How to determine the order of a reactant

Postby Juliet Stephenson 4E » Sun Mar 08, 2020 8:34 pm

I don't think this is the easiest way, but one important distinction is that different orders have differently shaped graphs of concentration vs time. You can tell what the order is by observing which concentration vs. time graph is linear. For first order reactions, ln[A] vs. time is linear. For second order reactions, 1/[A] vs. time is linear. For zeroth order reactions, [A] vs time is linear.


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