The rate constant for the reaction $2N_2O_5 \to 4NO_2 + O_2$ is $3.0 \times 10^{-5} \, sec^{-1}$. If the rate is $2.40 \times 10^{-5} \, M \, sec^{-1}$,then the concentration of $N_2O_5$ (in $M$) is?

The reaction of hydrogen and iodine monochloride is given as
$H_{2(g)} + 2ICl_{(g)} \to 2HCl_{(g)} + I_{2(g)}$
This reaction is of first order with respect to $H_{2(g)}$ and $ICl_{(g)}$. Which of the following mechanisms is consistent with the given information?
Mechanism $A$:
$H_{2(g)} + 2ICl_{(g)} \to 2HCl_{(g)} + I_{2(g)}$
Mechanism $B$:
$H_{2(g)} + ICl_{(g)} \to HCl_{(g)} + HI_{(g)}$ (Slow)
$HI_{(g)} + ICl_{(g)} \to HCl_{(g)} + I_{2(g)}$ (Fast)

For the reaction $A + B \rightarrow$ products,it is observed that
$(i)$ on doubling the initial concentration of $A$ only,the rate of reaction is also doubled and
$(ii)$ on doubling the initial concentration of both $A$ and $B$,there is a change by a factor of $8$ in the rate of the reaction.
The rate of this reaction is given by

The rate law for a reaction between reactants $A$,$B$,and $C$ is $r = K[A][B][C]^2$. If the concentration of $A$ is halved,then the rate of reaction:

For the reaction $X_{2(g)} + Y_{2(g)} \rightarrow 2XY_{(g)}$,the following data are observed:

$[X_{2}] \ (M)$	$[Y_{2}] \ (M)$	Rate of appearance of $XY \ (M \ sec^{-1})$
$0.1$	$0.1$	$5 \times 10^{-6}$
$0.2$	$0.1$	$10^{-5}$
$0.2$	$0.2$	$4 \times 10^{-5}$

Calculate the rate constant of the reaction (in $M^{1-n} \ sec^{-1}$),where $n$ is the order of the reaction.

State a condition under which a bimolecular reaction is kinetically first order reaction.