Question

A suggested mechanism for the gas phase decomposition of nitrous oxide is:

step 1 slow:   N₂O --> N₂ + O

step 2 fast:   N₂O + O --> N₂ + O₂

(1) What is the equation for the overall reaction? Use the smallest integer coefficients possible.

(2) Which species acts as a catalyst? Enter formula.

(3) Which species acts as a reaction intermediate? Enter formula.

(4) Complete the rate law for the overall reaction that is consistent with this mechanism.

(Use the form k[A]^m[B]ⁿ... , where '1' is understood (so don't write it) for m, n etc.)

Rate =

Answer 1

1)

Overall reaction is obtained by adding both the steps.

After adding both the steps:

N2O + N2O + O -> N2 + N2 + O + O2

Which on simplifying becomes:

2 N2O -> 2 N2 + O2

2 N2O -> 2 N2 + O2

2)

Catalyst should be reactant in 1st step and product in 2nd step.

No such compound here.

Answer: None

3)

O is intermediate because they are produced in step 1 and consumed in step 2

Answer: O

4)

Rate depends on slowest step.

Here 1st step is slowest

So, rate law is:

Rate = k [N2O]

Rate = k [N2O]