Question

For the reaction:2 H2 + 2 NO → N2 + 2 H2Othe observed rate expression, under some conditions, is:rate = k[H2][NO]Which of the following mechanisms are consistent with these data?Select all that are True.step 1 2 NO → N2O2 (slow) step 2 N2O2 + H2 → N2O + H2O (fast) step 3 N2O + H2 → N2 + H2O (fast)step 1 NO + NO ⇌ N2O2 (fast) step 2 N2O2 + H2 → N2 + H2O + O (slow) step 3 O + H2 → H2O (fast)step 1 2 NO ⇌ N2O2 (fast) step 2 N2O2 + H2 → N2O + H2O (slow) step 3 N2O + H2 → N2 + H2O (fast)step 1 H2 + 2 NO → N2O + H2O (slow) step 2 N2O + H2 → N2 + H2O (fast)

Answer 1

The correct mechanism for the reaction based on the given rate is:

Step 1 :
`H_(2) +2NO->N_(2)O+H_(2)O(slow)`

Step 2:
`2N_(2)O+H_(2) ->N_(2)+H_(2)O(fast)`

Step-by-step explanation:

The reaction rate of a muti-step reaction is determined by the slowest step of the reaction. Because of this reason, it is known as the rate-determining step of the reaction.

`rate = k[H_(2)][NO]`

The given rate expression has the concentrations of
`H_(2) , NO`.

This means that the slowest step of the mechanism must involve
`H_(2) ,NO`.

Among the proposed mechanisms, this criterion is met in the mechanism:

`Step 1 :H_(2) +2NO->N_(2)O+H_(2)O(slow)\\ Step 2:2N_(2)O+H_(2) ->N_(2)+H_(2)O(fast)`

( Reason: In the above mechanism the slowest step involves
`H_(2) ,NO`. )