For a chemical reaction,which of the following can never be a fraction?

For the reaction $A + B \rightarrow$ products,doubling the concentration of $A$ increases the reaction rate by four times,but doubling the concentration of $B$ has no effect on the reaction rate. What is the rate law?

For an elementary chemical reaction,$A_2 \underset{k_{-1}}{\overset{k_1}{\longleftrightarrow}} 2A$,the expression for $\frac{d[A]}{dt}$ is

For a chemical reaction,$2A + 2B \to C + D$,the order of reaction is $1$ with respect to $A$ and $1$ with respect to $B$. The initial rate of the reaction is $4 \times 10^{-2} \ mol \ L^{-1} \ s^{-1}$. When $50\%$ of the reactants are converted into products,the rate of the reaction would become:

The rate law of the reaction $A + 2B \to \text{Product}$ is given by $\frac{d[B]}{dt} = k[B^2]$. If $A$ is taken in excess,the order of the reaction will be

For the reaction,$CH_3Br_{(aq)} + OH_{(aq)}^{-} \rightarrow CH_3OH_{(aq)} + Br_{(aq)}^{-}$,the rate law is $\text{rate} = k[CH_3Br][OH^{-}]$. What is the change in the rate of reaction if the concentration of both reactants is doubled?