## first order reaction vs second order reaction

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

Alexis Robles 2k
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Joined: Wed Sep 18, 2019 12:18 am

### first order reaction vs second order reaction

What is the difference between the first-order and the second-order? When do we use one over the other? Thanks

Kimberly Koo 2I
Posts: 99
Joined: Sat Aug 17, 2019 12:17 am

### Re: first order reaction vs second order reaction

First order means that the concentration of a single reactant is raised to the first power. For a second order reaction, the concentration of 2 reactants is raised to the first power or the concentration of a single reactant is raised to the second power. The order of a reaction is determined by the sum of the powers of the concentrations of reactants in the rate law equation.

Ryan 1K
Posts: 101
Joined: Fri Aug 09, 2019 12:15 am

### Re: first order reaction vs second order reaction

If you have a graph, you can differentiate based on what graph shows a straight line (ln [A] vs $\frac{1}{[A]}$). If you have the rate laws or chemical equations, you can determine which order the reactions are based on the numbers and ratios of the reactants.