Determine the rate law for the rate$-$determining step.

From Step $1,$ we know that the first elementary reaction is rate$-$determining.

$HBr(g)+O_2(g)ra\frac{r}{r}HO$ OBr$(g)$

The rate law for an elementary step can be determined directly from the molecularity. In this case, the reaction is bimolecular hat$(v),$ because molecule$($s$)$ of the reactants is$/$are involved in this reaction. The order with respect to each reactant is therefore equal to

Since we know the order with respect to each reactant, we can write the rate law for this elementary reaction as the following. $($Rate expressions take the general form: rate $=k*[A{]}^a*[B{]}^b.)$

chemPad

Help

$\backslash$table$[[,],[$rate $=k[HBr{]}^2[O_2{]}^2,x$