Question

The reaction of nitric oxide (NO(g)) with molecular hydrogen (H2(g)) results in the formation of nitrogen and water as follows:

2NO (g) + 2H2(g)...> N2(g) + 2H2O(g)

The experimentally determined rate-law expression for this reaction is first order in H2(g) and second order with NO(g).

a) Is the reaction above, as written an elementary reaction?

b) One potential mechanism for this reaction is as follows:

H2(g) + 2NO(g)...> N2O (g) + H2O (g) k1

H2(g) + N2O (g)...> N2(g) + H2O(g) k2

Is this mechanism consistent with the experimental rate law? If not, why?

c) An alternative mechanism for the reaction is:

2NO(g) <...> N2O2(g) (fast) k1(fwd) k-1(rev)

H2(g) + N2O2 (g)...> N2O(g) + H2O(g) k2

H2(g) + N2O (g)...> N2(g) + H2O(g) k3

Show that this mechanism is consistent with the experimental law.