The effect of $pH$ on the rate constant for the hydrolysis of an ester is given by:

Given below are two statements:
Statement $I$: The rate law for the reaction $A + B \rightarrow C$ is rate $(r) = k[A]^2[B]$. When the concentration of both $A$ and $B$ is doubled,the reaction rate is increased "$x$" times.
Statement $II$: The figure shows the variation in concentration against time plot for a "$y$" order reaction.
Concentration of $R$ vs Time plot: $A$ straight line with a negative slope equal to $-K$.
The value of $x + y$ is . . . . . .

The rate constant for the first order decomposition of $H_{2}O_{2}$ is given by the following equation:
$\log k = 14.34 - 1.25 \times 10^{4} \, K / T$
Calculate $E_{a}$ for this reaction and at what temperature will its half-period be $256 \, min$?

The reaction of ozone with oxygen atoms in the presence of chlorine atoms can occur by a two-step process shown below:
$O_{3(g)} + Cl_{(g)}^{\bullet} \to O_{2(g)} + ClO_{(g)}^{\bullet}$ ..... $(i)$ $K_i = 5.2 \times 10^9 \ L \ mol^{-1} \ s^{-1}$
$ClO_{(g)}^{\bullet} + O_{(g)}^{\bullet} \to O_{2(g)} + Cl_{(g)}^{\bullet}$ ..... $(ii)$ $K_{ii} = 2.6 \times 10^{10} \ L \ mol^{-1} \ s^{-1}$
The closest rate constant for the overall reaction
$O_{3(g)} + O_{(g)}^{\bullet} \to 2O_{2(g)}$ is ........... $L \ mol^{-1} \ s^{-1}$

Which of the following relations is correct for the given reaction orders?

Half-lives of a first-order and a zero-order reaction are the same. Assume that the initial concentration of the reactant is the same for both reactions,then the ratio of the initial rates of the first-order reaction to that of the zero-order reaction is: