Question

The mechanism for the gas-phase reaction of nitrogen dioxide with carbon monoxide to form nitric oxide and carbon dioxide is thought to be:
NO2 + NO2 -------> NO3 + NO
NO3 + CO ---------> NO2 + CO2
1. Write the rate law expected for this mechanism. What is the overall balanced equation of the reaction?

Answer 1

Explanation:

$NO_2 + NO_2 \rightarrow NO_3 + NO$ (slow)..(1)

$NO_3 + CO\rightarrow NO_2 + CO_2$ (fast)..(2)

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

The reaction occurring in more than 1 step , the rate of the reaction is determined from the reaction which is occurring at slow speed.

So, the rate of reaction for the given mechanism will be determine by step 1.

Rate law expression of the given mechanism is :

$R=k[NO_2][NO_2]$

The rate law expected for this mechanism:

$R=K[NO_2]^2$

The overall balanced equation of the reaction :

=  [1] + [2]

$NO_2+CO\rightarrow CO_2+NO$