If the concentration of the reactants is increased,the rate of reaction

For a reaction,$I^{-} + OCl^{-} \to IO^{-} + Cl^{-}$ in an aqueous medium,the rate of reaction is given by $\frac{d[IO^{-}]}{dt} = K \frac{[I^{-}][OCl^{-}]}{[OH^{-}]}$. The overall order of reaction is

For the reaction $2NO + Cl_2 \rightarrow 2NOCl$,the following mechanism is proposed. What will be the rate law for the reaction? $NO + Cl_2 \rightleftharpoons NOCl_2$ (fast); $NOCl_2 + NO \rightarrow 2NOCl$ (slow)

For the reaction $A + B \rightarrow \text{product}$,the rate of reaction is $3.6 \times 10^{-2} \ mol \ dm^{-3} \ sec^{-1}$. When $[A] = 0.2 \ mol \ dm^{-3}$ and $[B] = 0.1 \ mol \ dm^{-3}$,calculate the rate constant of the reaction if the reaction is first order in $A$ and second order in $B$.

Rate of reaction is $r_1 = k[A]^a[B]^b$. If the concentration of $A$ is doubled and $B$ is halved,the new rate is $r_2$. What is the value of $\frac{r_2}{r_1}$?

Order of a reaction is decided by