NAME ___________________________________________
PERIOD __________
DATE ____________________________
CHAPTER 16: RATE LAWS
Remember that you must show work for points. Don’t forget units!
1. Determine the overall reaction order for a reaction between A and B for which the rate law is
rate = k[A]2[B]2.
2. Write the rate law for the reaction aA → bB if the reaction is third order in A. [B] is not part of
the rate law.
3. The rate law for the reaction 2NO(g) + O2(g) → 2NO2(g) is first order in O2 and third order
overall. What is the rate law for the reaction?
4. Assume that the rate law for a generic chemical reaction is rate = [A][B]3. What is the reaction
order in A, the reaction order in B, and the overall reaction order?
5. The following reaction is first order in H2 and second order in NO with a rate constant of 2.90 x
102 (L2/(mol2 ● s)). 2NO(g) + H2(g) → N2O(g) + H2O(g). Calculate the instantaneous rate when
the reactant concentrations are [NO] = 0.002M and [H2] = 0.004M.
6. The following reaction is first order in H2 and second order in NO with a rate constant of 2.90 x
102 (L2/(mol2 ● s)). 2NO(g) + H2(g) → N2O(g) + H2O(g). Calculate the instantaneous rate when
the reactant concentrations are [NO] = 0.01M and [H2] = 0.00125M.
7. Consider the generic chemical reaction: A + B → AB. Based on experimental date, the reaction
is second order in Reactant A. If the concentration of A is halved, and all other conditions
remain unchanged, how does the reaction rate change?
8. A two-step mechanism has been proposed for the decomposition of nitryl chloride (NO 2Cl).
What is the overall reaction? Identify any intermediates in the reaction sequence and explain
why they are intermediates.
 Step 1: NO2Cl(g) → NO2(g) + Cl(g)
 Step 2: NO2Cl(g) + Cl(g) → NO2(g) + Cl2(g)
9. Suppose that a chemical reaction takes place in a two-step mechanism. Which step in the
reaction mechanism is the rate-limiting step? Explain.
 Step 1 (fast) A + B → C
 Step 2 (slow) C + D → E
10. In the figure below, identify each of the labels 1, 2, 3, 4, and 5 as one of the following: activated
complex, intermediate, reactants, or products.