First order, second order reactions  [ENDORSED]

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Salma Sudarmadji 2I
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Joined: Fri Jul 15, 2016 3:00 am

First order, second order reactions

Postby Salma Sudarmadji 2I » Sat Feb 18, 2017 11:59 pm

What is an easy way to remember how to determine if a reaction is first order or second order?
Thanks

Chem_Mod
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Re: First order, second order reactions  [ENDORSED]

Postby Chem_Mod » Sun Feb 19, 2017 8:54 am

If a reaction is first-order, it will increase proportionally with the concentration of the reagent. If the reaction is second-order, it will increase 4-fold when the reagent concentration is doubled. There's no real need to memorize them - you can tell based off the superscript (n) on the rate laws if they're given. If the problem doesn't give you the entire rate law, there's usually a way to determine the order.

EmilyLeibovitch2E
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Joined: Wed Nov 18, 2015 3:00 am

Re: First order, second order reactions

Postby EmilyLeibovitch2E » Sun Feb 19, 2017 3:18 pm

Will we ever be asked to do a third or forth order reaction even though it wasn't covered in the course reader?

Jasmine_Esparza_2A
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Re: First order, second order reactions

Postby Jasmine_Esparza_2A » Sun Feb 19, 2017 9:14 pm

We are tested on everything up to page 73 in the course reader. This page ends with "Pre-equilibrium approach".

EmilyLeibovitch2E wrote:Will we ever be asked to do a third or forth order reaction even though it wasn't covered in the course reader?

Daisy Palomera 3B
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Joined: Wed Sep 21, 2016 2:58 pm

Re: First order, second order reactions

Postby Daisy Palomera 3B » Sun Feb 19, 2017 11:07 pm

Would one of the ways to determine the rate law, if it is not given, be to use initial rates?

904826427
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Joined: Wed Sep 21, 2016 2:55 pm

Re: First order, second order reactions

Postby 904826427 » Wed Feb 22, 2017 11:06 pm

Daisy Palomera 3B wrote:Would one of the ways to determine the rate law, if it is not given, be to use initial rates?


I don't see why not

Carolyn Huh 1K
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Re: First order, second order reactions

Postby Carolyn Huh 1K » Wed Feb 22, 2017 11:30 pm

The rate constant for a second order process depends on the initial concentration of a reactant, whereas this is of no concern for a first order reaction.


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