## Reaction Order

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

Bianca Barcelo 4I
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Joined: Fri Sep 28, 2018 12:17 am
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### Reaction Order

How does the reaction order affect the units of rate laws?

MaanasO 1A
Posts: 72
Joined: Fri Sep 28, 2018 12:26 am

### Re: Reaction Order

The final output should have the units M/s. So if you have higher than a 1st order reaction, you'll have extra M multiplied together => the k will have multiple 1/M to cancel everything out.

Clarissa Cabil 1I
Posts: 66
Joined: Fri Sep 28, 2018 12:19 am

### Re: Reaction Order

Given reaction A --> B (concentrations are in mol.L-1 and time is in s)

If this reaction is a zero order reaction, the units for its rate constants should be (mol A).L-1.s-1

If this reaction is a first order reaction, the units for its rate constants should be s-1

If this reaction is a second order reaction, the units for its rate constants should be L.(mol A)-1.s-1

Hope this helps!

Posts: 62
Joined: Fri Sep 28, 2018 12:15 am

### Re: Reaction Order

A general formula can be M^(1-p)*s^-1, where p is the overall order of the reaction.

Casandra
Posts: 65
Joined: Fri Sep 28, 2018 12:17 am

### Re: Reaction Order

For a zero order rate the units are mol/L*s
For a 1st order rate the units are 1/s
For a 2nd order rate the units are L/mol*s