The catalyst for the hydrolysis of cane sugar is ........

For any chemical reaction,what factors do chemists aim to determine?

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 . . . . . .

For a first order reaction,which of the following statements is correct?

Under identical reaction conditions,for a reactant with an initial concentration of $1.386 \, M$,the time taken for the concentration to become half is $40 \, s$ for a first-order reaction and $20 \, s$ for a zero-order reaction. The ratio of the rate constant of the first-order reaction $(K_1)$ to the rate constant of the zero-order reaction $(K_0)$ is ......... $mol \, L^{-1}$.

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