In the reaction sequence $A$ $\xrightarrow{K_1} B$ $\xrightarrow{K_2} C$ $\xrightarrow{K_3} D$,where $K_3 > K_2 > K_1$,which step determines the rate of the reaction?

For the reaction system $2NO_{(g)} + O_{2(g)} \to 2NO_{2(g)}$,the volume is suddenly reduced to half its initial value by increasing the pressure. If the reaction is of first order with respect to $O_2$ and second order with respect to $NO$,the rate of reaction will:

For the reaction $2H_2 + 2NO \to N_2 + 2H_2O$,the following mechanism has been proposed:
$I$. $2NO \rightleftharpoons N_2O_2$ (fast)
$II$. $N_2O_2 + H_2 \xrightarrow{k_2} N_2O + H_2O$ (slow)
$III$. $N_2O + H_2 \to N_2 + H_2O$ (fast)
What will be the rate law of this reaction?

For a gaseous reaction between $X$ and $Y$,$X + 3Y \rightarrow XY_3$,the initial rate data is given below:
$[X] = 0.1 \ M, [Y] = 0.1 \ M, \text{Rate} = 0.002 \ Ms^{-1}$
$[X] = 0.2 \ M, [Y] = 0.1 \ M, \text{Rate} = 0.002 \ Ms^{-1}$
$[X] = 0.3 \ M, [Y] = 0.2 \ M, \text{Rate} = 0.008 \ Ms^{-1}$
$[X] = 0.4 \ M, [Y] = 0.3 \ M, \text{Rate} = 0.018 \ Ms^{-1}$
What is the rate law?

What is the order and molecularity of the following reaction?
$NO_{2(g)} + NO_{2(g)} \longrightarrow 2NO_{(g)} + O_{2(g)}$

The rate law for the reaction $2 NO_{(g)} + O_{2(g)} \longrightarrow 2 NO_{2(g)}$ is $\text{rate} = k[NO]^2[O_2]$. Which of the following statements is correct?