For the reaction $2A + B \rightarrow \text{Product}$,the following mechanism is given. What is the order of the reaction?
$2A \rightleftharpoons A_2$ (fast)
$A_2 + B \rightarrow P$ (slow)

Which one of the following statements regarding the order of a reaction is not correct?

$A$ study of chemical kinetics of the reaction $A + B \to$ Products,gave the following data at $25 \ ^oC$.

$Exp. \ No.$	$[A]$	$[B]$	$Rate$
$1.$	$1.0$	$0.15$	$4.2 \times 10^{-6}$
$2.$	$2.0$	$0.15$	$8.4 \times 10^{-6}$
$3.$	$1.0$	$0.20$	$5.6 \times 10^{-6}$

Find out the rate law.

Consider the following single step reaction in gas phase at constant temperature.
$2 \ A_{(g)} + B_{(g)} \rightarrow C_{(g)}$
The initial rate of the reaction is recorded as $r_1$ when the reaction starts with $1.5 \ atm$ pressure of $A$ and $0.7 \ atm$ pressure of $B$. After some time,the rate $r_2$ is recorded when the pressure of $C$ becomes $0.5 \ atm$. The ratio $r_1 : r_2$ is $\qquad$ $\times 10^{-1}$.
(Nearest integer)

The dimension of the rate constant for a second-order reaction involves:

The rate of the simple reaction,$2NO + O_2 \to 2NO_2$,when the volume of the reaction vessel is doubled: