Question

Consider the following balanced final equation.

NO₂ + CO NO + CO₂
Which is the correct step(s) for this reaction mechanism?
O NO₂ + CO₂ + CO— NO + CO₂
a) step 1: NO₂ + NO₂ → NO + NO₃ (slow)
step 2: NO₃ + CO → NO₂ + CO₂ (fast)
b) step 1: NO + NO₃- NO + NO₃ (slow)
step 2: NO₃ + CO → NO + CO₂ (fast)
c) step 1: 2NO₂ + NO-> 2NO + NO₃ (slow)
step 2: NO₃ + CO → 2NO₂ + CO₂ (fast)
d) None of the above.

Answer 1

The correct step(s) for this reaction mechanism is option a), with step 1 as the rate-determining step. The mechanism is consistent with the observed rate law.

Step-by-step explanation:

The correct step(s) for this reaction mechanism is option a):

Step 1: NO₂ + NO₂ → NO + NO₃ (slow)

Step 2: NO₃ + CO → NO₂ + CO₂ (fast)

The rate-determining step in this mechanism is step 1, which is the slowest step in the overall reaction. The mechanism is consistent with the observed rate law for the reaction and the overall stoichiometry as the rate law is proportional to the concentration of NO₂ squared in step 1 and proportional to the concentration of NO₃ and CO in step 2. The overall reaction can be represented as NO₂ + CO → NO + CO₂.