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

If the order of the reaction $x + y \xrightarrow{hv} xy$ is zero,it means that the rate of

When the concentration of $A$ in the reaction $A + B \rightleftharpoons AB$ is doubled,the rate of reaction will be

Assertion: The order of a reaction can have a fractional value.
Reason: The order of a reaction cannot be determined from the balanced chemical equation of a reaction.

$A$ student has studied the decomposition of a gas $AB_3$ at $25^{\circ} C$. He obtained the following data.

$p \ (mm \ Hg)$	$50$	$100$	$200$	$400$
Relative $t_{1/2} \ (s)$	$4$	$2$	$1$	$0.5$

The order of the reaction is

For the reaction: $2 A + B \rightarrow A_2 B$,the rate $= k[A][B]^2$ with $k = 2.0 \times 10^{-6} \ mol^{-2} \ L^2 \ s^{-1}$. Calculate the initial rate of the reaction when $[A] = 0.1 \ mol \ L^{-1}$ and $[B] = 0.2 \ mol \ L^{-1}$. Calculate the rate of reaction after $[A]$ is reduced to $0.06 \ mol \ L^{-1}$.