Strategy for solving the problems involving reaction rates/ orders.

[Ben Apsley]

There's a specific kind of problem I've been struggling with:

I've been having difficulty with the problems where they give you a list of the reactant concentrations and initial rates, and you have to find the order of each reactant. I know you're supposed to use reactions where the concentrations for certain reactants stay the same, but I'm not entirely sure how?

Could someone give me a good strategy for doing this problems?

Thanks!

[Brandon Pham 1F]

Hi,
Essentially you take 2 experiements where all the concentrations of reactants are kept the same except for your reactant of interest and then you compare the rates of the 2 reactions. Its set up as
(reactant of exp 2)^a = rate 2
(reactant of exp 1)^a = rate 1

and then you solve for a (usually it will be a whole number which makes it easy to tell)

[106169087]

The method of initial rates involves seeing how the reaction rate changes when the reactant concentration changes. If a reactant concentration doubles and the reaction rate stays the same, it is zero order. If a reactant concentration doubles and the reaction rate also doubles, it is first order. If a reactant concentration doubles and the reaction rate quadruples, it is second order.