## 1st, 2nd, and 0 Order Reactions

$\frac{d[R]}{dt}=-k[R]; \ln [R]=-kt + \ln [R]_{0}; t_{\frac{1}{2}}=\frac{0.693}{k}$

Jaci Glassick 2G
Posts: 104
Joined: Sat Jul 20, 2019 12:16 am

### 1st, 2nd, and 0 Order Reactions

Can someone people explain the difference in 1st, 2nd, and 0 order reactions? I understand that you must use different equations when dealing with each, but I'm not sure how to tell the difference between them. Is that information given to you?

chrisleung-2J
Posts: 112
Joined: Fri Aug 09, 2019 12:17 am
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### Re: 1st, 2nd, and 0 Order Reactions

We did an example in class a few days ago showing how we can determine the order of individual reactants using a table of concentrations of each reactant and the resulting rate of reaction. The sum of the order of each individual reactant equals the overall order of the reaction.

ELu 1J
Posts: 51
Joined: Thu Jul 25, 2019 12:16 am

### Re: 1st, 2nd, and 0 Order Reactions

The difference between the three reactions is essentially the varying number of molecules needed to collide and react with each other for the reaction to proceed. You can calculate whether a reaction is 1st, 2nd, or 0th order by determining the orders of the individual reactants themselves, which can be done two ways: 1) Comparing the instantaneous initial reaction rates 2) Looking at which plot yields the most linear graph. Then you add the individual orders together together to get the order of the reaction.