For the reaction $XA + YB \rightarrow mp + nq$,the rate is given by $\text{Rate} = K[A]^c[B]^d$. What is the overall order of the reaction?

For the reaction:
$2NO_{2(g)} + O_{3(g)} \to N_2O_{5(g)} + O_{2(g)}$
The rate law is $R = K[NO_2]^1 [O_3]^1$.
Which of these possible reaction mechanisms is consistent with the rate law?
Mechanism $I$:
$NO_{2(g)} + O_{3(g)} \to NO_{3(g)} + O_{2(g)}$ (slow)
$NO_{3(g)} + NO_{2(g)} \to N_2O_{5(g)}$ (fast)
Mechanism $II$:
$O_{3(g)} \rightleftharpoons O_{2(g)} + [O]$ (fast)
$NO_{2(g)} + [O] \to NO_3$ (slow)
$NO_{3(g)} + NO_{2(g)} \to N_2O_5$ (fast)

The rate law for the reaction $A + B \rightarrow \text{product}$ is $\text{rate} = k[A][B]$. When will the rate of reaction increase by a factor of $2$?

Identify the reaction intermediate of the following reaction sequence:
$(i)$ $2 SO_{2(g)} + 2 NO_{2(g)} \rightarrow 2 SO_{3(g)} + 2 NO_{(g)}$
$(ii)$ $2 NO_{(g)} + O_{2(g)} \rightarrow 2 NO_{2(g)}$
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Overall: $2 SO_{2(g)} + O_{2(g)} \rightarrow 2 SO_{3(g)}$

The rate constant of which of the following reactions is independent of the concentration of the reactants?

For a reaction,$A + 2B \rightarrow$ Products,when the concentration of $B$ alone is increased,the half-life remains the same. If the concentration of $A$ alone is doubled,the rate remains the same. The unit of the rate constant for the reaction is: