Practice Test 2
Note: These questions are representative of the types you can expect on the test.
The actual test will be longer, typically between 20-40 questions.
You will need to bring a SCANTRON and pencil to each class test.
Instructions: Select the best answer then click on "get answer" box.
Question 1. For the reaction, C6H14 (g) ®
C6H6 (g) + 4 H2 (g),
DP(C6H14)/D t was found to be -6.2 x 10-3 atm/sec.
Determine the value of DP(H2)/Dt at the same time.
Question 2. The reaction, A + 2 B ® products, was found to have the following rate law: rate = [A][B]2
While holding the concentration of A constant, the concentration of B was increased three fold. Predict by what factor the rate of the reaction will increase.
Question 3. The units for a first-order rate constant are:
Question 4. Nitric oxide reacts with hydrogen to form nitrous oxide and water. Use the following data to determine the rate equation for the reaction.
2 NO + H2 ® N2O + H2O
Expt.# [NO]o [H2]o Initial Rate
1 0.021 0.065 1.46 M/min
2 0.021 0.260 1.46 M/min
3 0.042 0.065 5.84 M/min
Question 5. Ammonium ion (NH4+) reacts with nitrite ion (NO2-) according to the following equation:
NH4+ (aq) + NO2- (aq) ® N2 (g) + 2 H2O (l)
The following initial rates of reaction have been measured for the given reactant concentrations:
Expt.# [NH4+] [NO2-] Rate (M/hr)
1 0.010 0.020 0.020
2 0.020 0.020 0.040
3 0.010 0.010 0.005
Which of the following is the rate law (rate equation) for this reaction?
Question 6. An increase in the temperature of the reactants causes an increase in the rate of reaction. The best explanation is: As the temperature increases
Question 7. Complete the statement: A catalyst
Question 8. Suppose that the reaction: Cl2 (g) + 3 F2 (g) ® 2 ClF3 (g)
is first order in F2 and second order in Cl2. Which of the following is not true?
Question 9. The equilibrium constant expression for the reaction below is:
2 BrF5 (g) ⇋ Br2 (g) + 5 F2 (g)
Question 10. Kc = 0.040 for the reaction below at 450oC. If a reaction begins with 0.40 mole of Cl2 and 0.20 mole of PCl3 in a 1.0 liter container,
what is the concentration of Cl2 at equilibrium?
PCl3(g) + Cl2(g) ⇋ PCl5(g)
Question 11. At 700 K, the reaction: 2 SO2 (g) + O2 ⇋ 2 SO3 (g)
has an equilibrium constant Kc = 4.3 x 106, and the following concentrations are present:
[SO2]eq = 0.010 M [SO3]eq = 10 M [O2]eq = 0.010 M
Is the mixture at equilibrium, yes or no? If not at equilibrium, in which direction, left to right, or right to left, will reaction occur to reach equilibrium?
Question 12. For the following reaction at equilibrium, which one of the changes below would cause the equilibrium to shift to the left?
2 NOBr (g) ⇋ 2 NO (g) + Br2 (g) DHo = 30 kJ
Question 13. Consider the following equilibrium system:
PCl5 ⇋ PCl3 + Cl2 DHo = +87.8 kJ
Which of the following statements is false?