If the order of a reaction is $x$,then the unit of its rate constant is:

If the surface area of the reactants increases,then the order of the reaction:

For the reaction $NO_2 + CO \rightarrow CO_2 + NO$,the rate law is given as $\text{Rate} = K [NO_2]^2$. What is the number of $CO$ molecules participating in the slow step?

If in a certain reaction,two different reactants take part,then:

Identify the order of the following reaction: $2 NO_{2(g)} \longrightarrow 2 NO_{(g)} + O_{2(g)}$

The rate constants for the following reactions are:
Reaction $1$: $A \xrightarrow{\text{catalyst } 1} P_1, k_1 = 1 \ s^{-1}$
Reaction $2$: $A \xrightarrow{\text{catalyst } 2} P_2, k_2 = 0.1 \ L \ mol^{-1} \ s^{-1}$
Reaction $3$: $A \xrightarrow{\text{catalyst } 3} P_3, k_3 = 0.01 \ L^2 \ mol^{-2} \ s^{-1}$
What is the correct relation between the rates of the reactions at $[A] = 1 \ M$?