TopScore test 2, gen chem Q53

[mddang]

---

Members do not see this ad.

Ozone, O3 decomposes to O2..
Overall rxn: 2 O3 (g) --> 3 O2 (g)


Determine the rate law.

Step 1 (fast, reversible): O3(g) <--> O2(g) + O (g)

Step 2 (slow): O3(g) + O(g) --> 2 O2(g)


Answer: Rate = k[O3][O]




My question is can intermediates that aren't present in the overall reaction be present in the rate law?


I was thinking the rate law would be rate = k[O3]^2


Thanks

 

[Glycogen]

Ozone, O3 decomposes to O2..
Overall rxn: 2 O3 (g) --> 3 O2 (g)


Determine the rate law.

Step 1 (fast, reversible): O3(g) <--> O2(g) + O (g)

Step 2 (slow): O3(g) + O(g) --> 2 O2(g)


Answer: Rate = k[O3][O]






My question is can intermediates that aren't present in the overall reaction be present in the rate law?


I was thinking the rate law would be rate = k[O3]^2


Thanks

Rate law is the rate of the slowest step.

 

[mddang]

Rate law is the rate of the slowest step.

I understand that, but I was unsure of the correct answer because of the fact that the O is not in the overall reaction.

From the slow step alone, I would first say rate = k[O3][O].

BUT O is an intermediate. The first step shows that O is formed from the dissociation of O3, so in the rate law, I would substitute [O] for [O3].

rate = k[O3]^2


Am I incorrect?