Exam 3 ch 14 reaction mechanisms

Question 1

Mechanism and rate law

Answer 1

• Steps that make up reaction mechanism must lead to a rate law observed in experiments

Question 2

Elementary reaction

Answer 2

-Individual steps in overall reaction

Question 3

Overall reaction

Answer 3

-Sum of all elementary steps

Question 4

Reaction intermediates

Answer 4

-Formed in one step and consumed in another
-Can isolate unlike activated complex

Question 5

Molecularity

Answer 5

-Number of molecules on reactant side for elementary reaction

Unimolecular: 1
Bimolecular: 2
Termolecular: 3

Question 6

Rate law slow step first/1 step

Answer 6

-Rate law = slow step rate law coefficients
-Slow step is rate-limiting step

-If reaction occurs in 1 step, rate law is equal to the rate law of that step

Question 7

Rate law elementrary steps

Answer 7

-Follows directly from coefficients

Question 8

Rate law fast first step

Answer 8

1. Look at slow step and make rate law, is there something that isnt in overall reaction reactants or made then used?
2. Eliminate intermediate using fast equilibrium

foward rate = reverse rate solve for intermediate

3. Substitute into that spot for slow step

koverall = k2 * k1 / k-1

4. write overall rate and see if it matches experimental

Question 9

Catalyst vs reaction intermediates

Answer 9

Catalyst are not consumed but intermediates are

Both not in overall reaction