Fill in the blanks:
$1.$ The rate of a zero order reaction depends on the ........... concentration of the reactant.
$2.$ The molecularity of the slow step is equal to the ........... of the overall reaction.
$3.$ Rate $=$ ........ $[A]^x [B]^y$

Consider the reaction:
$Cl_{2(aq)} + H_2S_{(aq)} \rightarrow S_{(s)} + 2H^{+}_{(aq)} + 2Cl^{-}_{(aq)}$
The rate equation for this reaction is:
$\text{rate} = k[Cl_2][H_2S]$
Which of these mechanisms is/are consistent with this rate equation?
$A.$ $Cl_2 + H_2S \rightarrow H^{+} + Cl^{-} + Cl^{+} + HS^{-}$ (slow)
$Cl^{+} + HS^{-} \rightarrow H^{+} + Cl^{-} + S$ (fast)
$B.$ $H_2S \rightleftharpoons H^{+} + HS^{-}$ (fast equilibrium)
$Cl_2 + HS^{-} \rightarrow 2Cl^{-} + H^{+} + S$ (slow)

Consider the following reactions:
$A$ $\rightarrow P_1; B$ $\rightarrow P_2; C$ $\rightarrow P_3; D$ $\rightarrow P_4$
The orders of the above reactions are $a, b, c,$ and $d,$ respectively. The following graph is obtained when $\log[\text{rate}]$ vs. $\log[\text{conc.}]$ are plotted:
Among the following,the correct sequence for the order of the reactions is:

Determine the order of reaction on the basis of following data for the reaction $A + B \to C$.

Exp.	$[A]$	$[B]$	Rate of reaction $(mol \ L^{-1} \ s^{-1})$
$1$	$0.1$	$0.1$	$2 \times 10^{-3}$
$2$	$0.4$	$0.1$	$0.8 \times 10^{-2}$
$3$	$0.1$	$0.2$	$1.6 \times 10^{-2}$

(in $.5$)

Why is the hydrolysis of an ester slow at the beginning and fast after some time?

The rate law for the decomposition of hydrogen iodide is $-\frac{d[HI]}{dt}=k[HI]^2$. The units of rate constant $k$ are