Determining the order of reaction from the rate law: Bromide ion is oxidized by bromate ion in acidic solution. `5Br^(-)(aq.)+BrO_(3)^(-)(aq.)+6H^(+)(aq.)rarrBr_(2)(aq.)+3H_(2)O(l)`
The expermentally determined rate law is
`"Rate" = k[Br^(-)][BrO_(3)^(-)][H^(+)]^(2)`
What is the order of reaction with respect to each of the reactants and what is teh overall reaction order ?
Strategy : To find the reaction order with respect to each reactant, look at the exponents in the rate law, not the coefficients in the balanced chemical equation, and then sum the exponents to obtain the overall reaction order.

Explanation

Because the exponewnt on `[Br^(-)]` (understood) is 1, the reaction is first order with respect to `Br^(-)` (an order with respect to a species equals the exponent of its concentration). Similary, the reaction is first order with respect to `BrO_(3)^(-)` qand is second order with repect to `H^(+)`. The reaction is fourth order overall because the sum of the exponents `(1+1+2)` is 4.