Question

The macro rate law for conversion of nitrogen monoxide from auto exhausts into the brown smog pollutant nitrogen dioxide, 2 NO (g) + O2 (g) → 2 NO2 (g) is: rate-k[NOF [02] Six mechanisms proposed. When艹appears, means elementary step is an equilibrium reaction: Mech A NO (g) + NO (g) N2O2 (g) fast slow fast fast slow slow fast slow fast O2 (g) → N2O2 (g) NO (g) + O (g) NO2 (g) + NO (g) → N2O3 (g) N2O3 (g) + 0(g) → 2NO2(g) NO(g) NO (g) 2 NO (g) → NO2 (g)+ N (g) N (g) NO (g) NO3(g) 2 NO (g) + O2(g) → + 2NO2 (g) Mech B NO2 (g) NO2 (g) NO2 (g) O(g) O2 (g) → 0(g) Mech C + + + → Mech D O2 (g) → NO2 (g) + N03 (g) fast O2 (g) NO (g) + Mech E → 2 NO2 (g) slow + Mech F 2NO2(g) (o) Which of these mechanisms can be eliminated as being viable, and explain your reasoning for each

After your selection in a if more than one mechanism is still plausible propose possible experiment that could help determine which of the remaining mechanisms might be further validated

Answer 1

2NO +O2 ------> 2NO2

Rate = K[NO]²[O2]

Rate of reaction depends upon slowest step . So slowest step is called rate determing step.

2NO --------> NO2 + N slow    

N + O2 ------> NO2 fast step

rate = K [NO]²     D answer