1. GENERAL CHEMISTRY-II (1412)
S.I. # 22
Practice Test 3
1. Consider the following reaction:
3A  2B
The average rate of appearance of B is given by ∆[B]/ ∆t. Comparing the rate of appearance of B
and the rate of disappearance of A, we get ∆[B]/ ∆ = ________x (-∆[A]/ ∆t).
A) +3/2 B) +2/3 C) +1 D) -3/2 E) -2/3
2. Which of the following is not a valid expression for the rate of the reaction below?
_______________
4NH3 + 7O2  4NO2 + 6H2O
A) 1 ∆ [H2O]
6 ∆t
B) -1 ∆ [NH3]
4 ∆t
C) 1 ∆ [NO2]
4 ∆t
D) - 1 ∆ [O2]
7 ∆t
E) All of the above are valid expressions of the reaction rate.
3. Of the unit below, __________ are appropriate for a second-order reaction rate constant.
A) mol/L B) L mol-1s-1 C) s-1 D) Ms-1 E) M-1s-1
4. The kinetics of the reaction below were studied and it was determined that the reaction rate
increased by a factor of 9 when the concentration of B was tripled. The reaction is __________ order
in B.
A + B  P
A) zero B) first C) second D) third E) one-half
5. The data in the table below were obtained for the reaction:
A + B  P
Experiment Number [A] (M) [B] (M) Initial Rate (M/s)
1 0.273 0.763 2.83
2 0.273 1.526 2.83
3 0.819 0.763 25.47
The order of the reaction in A is __________.
A) 1 B) 2 C) 3 D) 4 E) 0

2. 6. The order of the reaction in B is ___________.
A) 1 B) 2 C) 3 D) 4 E) 0
7. The overall reaction order is ___________.
A) 1 B) 2 C) 3 D) 4 E) 0
8. The magnitude of the rate constant is ____________.
A) 13.2 B) 42.0 C) 0.278 D) 38.0 E) 2.21
9. A catalyst can increase the rate of a reaction ______________.
A) by lowering the overall activation energy (Ea) of the reaction
B) by changing the value of the frequency factor (A)
C) by lowering the activation energy of the reverse reaction
D) by providing an alternative pathway with a lower activation energy
10. In general, as temperature goes up, reaction rate ___________.
A) goes up if the reaction is endothermic
B) stays the same if the reaction is first order
C) stays the same regardless of whether the reaction is exothermic or endothermic
D) goes up regardless of whether the reaction is exothermic or endothermic
E) goes up if the reaction is exothermic
11. The mechanism for formation of the product X is:
A + B  C +D (slow)
B + D  X (fast)
The intermediate reactant in the reaction is _____________.
A) A B) B C) C D) D E) X
12. The rate for A + B  C + D (slow)
B + D  X (fast)
Is given by ______________
A) rate = k[A]
B) rate = k[A][C]
C) rate = k[A]2
D) rate = k[A][B]
E) rate = k[B][D]

3. 13. The relationship between the rate constant for the forward and reverse reactions and the
equilibrium constant for the process is Keq = ________________.
A) kf-kr B) kf/kr C) kfkr D) kr/kf E) kf+kr
14. The value of Keq for the equilibrium H2(g) +I2(g)  2 HI (g) is 794 at 25°C. What is the value
of Keq for ½ H2(g) + ½ I2(g)  HI(g)? _____________
A) 397 B) 28 C) 0.0013 D) 0.035 E) 1588
15. The value of Keq for the equilibrium H2(g) +I2(g)  2 HI (g) is 794 at 25°C . At this
temperature, what is the value of Keq for HI(g) ½ H2(g) + ½ I2(g) ? ___________.
A) 0.035 B) 1588 C) 0.0013 D) 28 E) 397
16. A reaction vessel is charged with hydrogen iodide, which partially decomposes to molecular
hydrogen and iodine: 2 HI (g)  H2(g) +I2(g) When the system comes to equilibrium at 425°C, PHI
= 0.708 atm, and PH2 = PI2 = 0.0960 atm. The value of Kp at this temperature is _____________.
A) 54.3
B) 1.84 x 10-2
C) Kp can not be calculated for this gas reaction when the volume of the reaction vessel is
not given.
-2
D) 1.30 x 10
E) 6.80 x 10-2
17. A reaction vessel is charged with hydrogen iodide, which partially decomposes to molecular
hydrogen and iodine: 2 HI (g)  H2(g) +I2(g) When the system comes to equilibrium at 425°C, PHI
= 0.708 atm, and PH2 = PI2 = 0.0960 atm. The value of Kc at this temperature is _____________.
A) 1.30 x 10-2
B) 1.84 x 10-2
C) Kc can not be calculated for this reaction
D) 6.80x 10-2
E) 54.3
18. At 22°C, Kp = 0.070 for the equilibrium: NH4HS (s)  NH3 (g) + H2S (g) A sample of solid
NH4HS is placed in a closed vessel and allowed to equilibrate. Calculate the equilibrium partial
pressure (atm) of ammonia, assuming that some solid NH4HS remains. ______________
A) 3.8 B) 4.9 x 10-3 C) 0.26 D) 0.070 E) 0.52

4. 19. How does the reaction quotient of a reaction (Q) differ from the equilibrium constant (Keq) of
the same reaction? ________________
A) Keq does not change with temperature, whereas Q is temperature dependent
B) Q does not change with temperature
C) K does not depend on the concentrations or partial pressures of reaction components.
D) Q is the same as Keq when a reaction is at equilibrium
E) Q does not depend on the concentrations or partial pressures of reaction components.
20. Which of the following is true concerning the Haber process? ____________.
A) It is a process used for the synthesis of ammonia
B) It is a process for the synthesis of elemental chlorine
C) It is an industrial synthesis of sodium chloride that was discovered by Karl Haber
D) it is another way of stating LeChatelier’s principle
E) It is a process used for shifting equilibrium positions to the right for more economical
chemical synthesis of a variety of substances
21. Which one of the following will change the value of an equilibrium constant? ___________.
A) varying the initial concentrations of products
B) changing the volume of the reaction vessel
C) adding other substances that do not react with any of the species involved in the
equilibrium
D) varying the initial concentrations of reactants
E) non of these will change the value
22. The reaction below is exothermic:
2SO2 (g) O2 2SO3 (g)
Le Chatelier’s Principle predicts that _____________ will result in an increase in the number of
moles of SO3 (g) in the reaction container.
A) increasing the pressure
B) increasing the volume of the container
C) increasing the temperature
D) removing some oxygen
E) decreasing the pressure

5. 23. Consider the following reaction at equilibrium 2NH3 (g)  N2 (g) + 3H2 (g) ∆H°C = + 92.4 kJ
Le Chatelier’s principle predicts that adding N2 (g) to the system at equilibrium will result in
______________.
A) a decrease in the concentration of H2 (g)
B) an increase in the value of the equilibrium constant
C) a lower partial pressure of N2
D) a decrease in the concentration of NH3 (g)
E) removal of all the H2 (g)
24. Of the follwing equilria, only ___________ will shift to eth left in response to a decrease in
volume.
A) 2HI (g)  H2 (g) + I2(g)
B) N2(g) + 3H2 (g)  2NH3 (g)
C) 2 SO3 (g)  2 SO2 (g) + O2(g)
D) 4 Fe (s) + 3O2  2 Fe2O3 (s)
E) H2 (g) + Cl2  2 HCl (g)
TRUE/FALSE
25. Rates of reaction can be positive or negative. __________
26. The relationship between the concentrations of reactants and products of a system at equilibrium
is given by the law of mass action. __________
27. The effect of a catalyst on chemical reaction is to react with product, effectively removing it and
shifting the equilibrium to the right. __________
BONUS
BONUS (NOMENCLATURE) ON BACK OF SCATRON AS SHOWN!
NAME FOR FORMULA FOR
+
1 NH 6 Ozone
2 NO2 7 Ethylene
3 N2O5 8 Ammonia
4 H2O2 9 Hydrochloric acid
5 PBCl2 10 Hydrogen Iodide

6. KEY
1. B
2. E
3. E
4. C
5. B
6. E
7. B
8. D
9. D
10. D
11. D
12. D
13. B
14. B
15. A
16. B
17. B
18. C
19. D
20. A
21. E
22. A
23. A
24. C
25. F
26. T
27. F
BONUS NOMENCLATURE
NAME FOR FORMULA FOR
+
1 NH Amonium ion 6 Ozone O3
2 NO2 nitrogen dioxide 7 Ethylene C 2H 4
3 N2O5 dinitrogen pentoxide 8 Ammonia NH3
4 H2O2 hydrogen peroxide 9 Hydrochloric acid HCl (aq)
5 PBCl2 Lead II chloride 10 Hydrogen Iodide HI