If doubling the concentration of a reactant $A$ increases the rate $4$ times and tripling the concentration of $A$ increases the rate $9$ times,the rate is proportional to

An example of a pseudo-$unimolecular$ reaction is

For the reaction $2A + B \rightarrow \text{product}$,the rate of the reaction is $15 \times 10^{-2} \ mol \ dm^{-3} \ sec^{-1}$ when $[A] = 0.3 \ mol \ dm^{-3}$ and $[B] = 0.05 \ mol \ dm^{-3}$. What is the value of the rate constant if the reaction is first order in both the reactants?

$A$ reaction is first order with respect to $A$ and second order with respect to $B$. What is the effect on the reaction rate if the concentration of $B$ is increased $3$ times?

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 $Cl_{2(aq)} + H_2S_{(aq)} \to S_{(s)} + 2H^+_{(aq)} + 2Cl^-_{(aq)}$, the rate law is given by $\text{Rate} = K[Cl_2][H_2S]$. Which of the following mechanisms is consistent with this rate law?
$(A)$ $Cl_2 + H_2S \to H^+ + Cl^- + Cl^+ + HS^-$ (slow); $Cl^+ + HS^- \to H^+ + Cl^- + S$ (fast)
$(B)$ $H_2S \rightleftharpoons H^+ + HS^-$ (fast equilibrium); $Cl_2 + HS^- \to 2Cl^- + H^+ + S$ (slow)