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Topic: Rate equation  (Read 4711 times)

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Offline SarahM

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Rate equation
« on: June 18, 2008, 07:51:09 AM »
Dear all,

How can I find the rate equation of a chemical reaction?

Thanks

Offline organic_god

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Re: Rate equation
« Reply #1 on: July 17, 2008, 09:11:57 PM »
alas for the rate equation can not be determined from the overal reaction equation alone.

you need to do a series of experiments.
in each experiment change the concentration of one reactant only.
example A + B ---> C

start with 1M A and 1M B.
next experiment 2M A and 1M B

then at a certain point in the reaction you need to quench it and find out how much C you got.
you can then make comparisons and see how changing the concentration effects the rate.

you can then see the order of reaction with respect to the reactants.
so if doubling concentration of A doubles rate then reaction is first order with respect to A

you end up with an equation that is along the lines of

rate = k[A]^n.^m

k is the rate constant
m and n are the orders of reaction

Offline eugenedakin

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Re: Rate equation
« Reply #2 on: July 18, 2008, 03:00:33 PM »
Hello organic_god,

Great response!!!

Sincerely,

Eugene
There are 10 kinds of people in this world: Those who understand binary, and those that do not.

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