Review Chapter 12 Physical Properties of Solutions
2.
Which response lists all the following pairs that are miscible liquids.
Pair # 1. octane (C8H18) and water
Pair # 2. acetic acid (CH3COOH) and water
Pair # 3. octane (C8H18) and carbon tetrachloride (CCl4)
A.
B.
C.
D.
E.
5.
9.
1, 3
1, 2
3
2
2, 3
Which of the following gives the molarity of a 17.0% by mass solution of sodium acetate, CH3COONa
(molar mass = 82.0 g/mol) in water? The density of the solution is 1.09 g/mL.
A. 2.26  10-6 M
B. 0.207 M
C. 2.07 M
D. 2.26 M
E. 2.72 M
What is the percent CsCl by mass in a 0.711 M CsCl solution that has a density of 1.091 g/mL?
A.
B.
C.
D.
E.
3.87  10-4 %
3.87  10-1 %
11.0 %
1.1 %
6.5  10-2 %
11. How many grams of water are needed to dissolve 27.8 g of ammonium nitrate NH4NO3 in order to prepare
a 0.452 m solution?
A.
B.
C.
D.
E.
769 g
36.2 g
100. g
0.157 g
157 g
21. The solubility of oxygen in lakes high in the Rocky Mountains is affected by the altitude. If the solubility
of O2 from the air is 2.67  10-4 M at sea level and 25C, what is the solubility of O2 at an elevation of
12,000 ft where the atmospheric pressure is 0.657 atm? Assume the temperature is 25C, and that the mole
fraction of O2 in air is 0.209 at both 12,000 ft and at sea level.
A.
B.
C.
D.
E.
1.75  10-4 M
2.67  10-4 M
3.66  10-5 M
4.06  10-4 M
none of these
25. According to Raoult's law, which statement is false?
A.
B.
C.
D.
E.
The vapor pressure of a solvent over a solution decreases as its mole fraction increases.
The solubility of a gas increases as the temperature decreases.
The vapor pressure of a solvent over a solution is less than that of pure solvent.
The greater the pressure of a gas over a solution the greater its solubility.
Ionic solutes dissociate in solution causing an enhancement of all colligative properties.
28. A solution is 40.0% by volume benzene (C6H6) in carbon tetrachloride at 20C. The vapor pressure of pure
benzene at this temperature is 74.61 mmHg and its density is 0.87865 g/cm3; the vapor pressure of pure
carbon tetrachloride is 91.32 mmHg and its density is 1.5940 g/cm3. If this solution is ideal, its total vapor
pressure at 20C is
A.
B.
C.
D.
E.
84.64 mmHg.
84.30 mmHg.
82.96 mmHg.
81.63 mmHg.
165.93 mmHg.
32. What is the freezing point of a solution that contains 10.0 g of glucose (C6H12O6) in 100. g of H2O? Kf for
water is 1.86C/m.
A.
B.
C.
D.
E.
-0.186C
+0.186C
-0.10C
+0.10C
-1.03C
33. Which of the following aqueous solutions has the highest boiling point?
Kb for water is 0.52C/m.
A.
B.
C.
D.
E.
0.2 m KCl
0.2 m Na2SO4
0.2 m Ca(NO3)2
0.2 m KCl AND 0.2 m Na2SO4
0.2 m Na2SO4 AND 0.2 m Ca(NO3)2
34. Which of the following aqueous solutions has the highest osmotic pressure at 25C?
A.
B.
C.
D.
0.2 M KBr
0.2 M ethanol
0.2 M Na2SO4
0.2 M KCl
36. Calculate the freezing point of a solution made from 22.0 g of octane (C8H18) dissolved in 148.0 g of
benzene. Benzene freezes at 5.50C and its Kf value is 5.12C/m.
A.
B.
C.
D.
E.
-1.16C
0.98C
6.66C
12.2C
5.49C
45. What volume of water should be added to 600. mL of ethanol in order to have a solution that boils at
95.0C?
[For ethanol, Kb = 1.22C/m, density = 0.789 g/cm3, boiling point = 78.4C]
A.
B.
C.
D.
E.
186 mL
245 mL
518 mL
116 mL
322 mL
48. What is the boiling point of an aqueous solution of a nonelectrolyte that has an osmotic pressure of 10.50
atm at 25C? Kb of water is 0.52C/m. Assume the density of the solution is the same as that of pure
water.
A.
B.
C.
D.
E.
0.22C
0.429C
100.43C
99.78C
100.22C
51. An aqueous fructose solution having a density of 1.049 g/cm3 is found to have an osmotic pressure of 17.0
atm at 25C. Find the temperature at which this solution freezes.
[Given: for water Kf = 1.86C/m; molecular mass of fructose = 180.16 g/mol]
A.
B.
C.
D.
E.
-1.52C
-1.30C
-1.57C
-1.69C
-1.41C
52. Consider a 0.90 M Al(NO3)3 solution. This solution has a nitrate ion concentration of
A.
B.
C.
D.
E.
0.30 M.
0.90 M.
0.0 M.
8.1 M.
2.7 M.
57. Arrange the following aqueous solutions in order of increasing boiling points.
0.050 m Mg(NO3)2; 0.100 m ethanol; 0.090 m NaCl
A.
B.
C.
D.
E.
Mg(NO3)2 < NaCl < ethanol
ethanol < Mg(NO3)2 < NaCl
ethanol < NaCl < Mg(NO3)2
NaCl < ethanol < Mg(NO3)2
Mg(NO3)2 < ethanol < NaCl
58. The osmotic pressure of a 0.010 M MgSO4 solution at 25C is 0.318 atm. Calculate i, the van't Hoff factor,
for this MgSO4 solution.
A.
B.
C.
D.
E.
0.013
1.3
1.5
2.0
76.8
Chapter 12 Physical Properties of Solutions Key
1.D
2.E
3.E
4.D
5.D
6.A
7.D
8.C
9.C
10.C
11.A
12.D
13.E
14.D
15.B
16.E
17.C
18.B
19.B
20.A
21.A
22.C
23.A
24.E
25.A
26.B
27.C
28.B
29.D
30.E
31.C
32.E
33.E
34.C
35.A
36.A
37.E
38.D
39.A
40.D
41.E
42.E
43.A
44.C
45.D
46.A
47.E
48.E
49.A
50.B
51.E
52.E
53.D
54.C
55.E
56.B
57.B
58.B
Chapter 13 Chemical Kinetics
3.
For the following reaction, P(C6H14)/t was found to be -6.2  10-3 atm/s.
C6H14(g)  C6H6(g) + 4H2(g)
Determine P(H2)/t for this reaction at the same time.
A.
B.
C.
D.
E.
5.
For the hypothetical reaction A + 3B  2C, the rate of appearance of C given by ([C]/t) may also be
expressed as
A.
B.
C.
D.
6.
6.2  10-3 atm/s
1.6  10-3 atm/s
2.5  10-2 atm/s
-1.6  10-3 atm/s
-2.5  10-2 atm/s
[C]/t = [A]/t
[C]/t = -(3/2) [B]/t
[C]/t = -(2/3) [B]/t
[C]/t = -(1/2) [A]/t
For the overall chemical reaction shown below, which one of the following statements can be rightly
assumed?
2H2S(g) + O2(g)  2S(s) + 2H2O(l)
A.
B.
C.
D.
E.
7.
The reaction A + 2B  products has been found to have the rate law, rate = k[A] [B]2. While holding the
concentration of A constant, the concentration of B is increased from x to 3x. Predict by what factor the
rate of reaction increases.
A.
B.
C.
D.
E.
8.
The reaction is third-order overall.
The reaction is second-order overall.
The rate law is, rate = k[H2S]2 [O2].
The rate law is, rate = k[H2S] [O2].
The rate law cannot be determined from the information given.
3
6
9
27
30
For the hypothetical reaction A + 3B  2C, the rate should be expressed as
A.
B.
C.
D.
E.
rate = [A]/t
rate = -[C]/
rate = -3([B]/t)
rate = (1/2)([C]/t)
rate = (1/3)([B]/t)
11. The reaction A + 2B  products was found to follow the rate law, rate = k[A]2[B]. Predict by what factor
the rate of reaction will increase when the concentration of A is doubled, the concentration of B is tripled,
and the temperature remains constant.
A.
B.
C.
D.
E.
5
6
12
18
none of these
13. It takes 42.0 min for the concentration of a reactant in a first-order reaction to drop from 0.45 M to 0.32 M
at 25C. How long will it take for the reaction to be 90% complete?
A.
B.
C.
D.
E.
13.0 min
86.0 min
137 min
222 min
284 min
15. Use the following data to determine the rate law for the reaction
2NO + H2  N2O + H2O.
A.
B.
C.
D.
E.
rate = k[NO]
rate = k[NO]2
rate = k[NO][H2]
rate = k[NO]2[H2]
rate = k[NO]2[H2]2
17. At 25C the rate constant for the first-order decomposition of a pesticide solution is 6.40  10-3 min-1. If
the starting concentration of pesticide is 0.0314 M, what concentration will remain after 62.0 min at
25C?
A.
B.
C.
D.
E.
1.14  10-1 M
47.4 M
-8.72.0 M
2.11  10-2 M
2.68  10-2 M
18. A certain first-order reaction A  B is 25% complete in 42 min at 25C. What is the half-life of the
reaction?
A.
B.
C.
D.
E.
21 min
42 min
84 min
120 min
101 min
21. A first-order reaction has a rate constant of 3.00  10-3 s-1. The time required for the reaction to be 75.0%
complete is
A.
B.
C.
D.
E.
95.8 s.
462 s.
231 s.
201 s.
41.7 s.
26. The isomerization of cyclopropane to form propene
is a first-order reaction. At 760 K, 85% of a sample of cyclopropane changes to propene in 79.0 min.
Determine the rate constant for this reaction at 760 K.
A.
B.
C.
D.
E.
3.66  10-2 min-1
1.04  10-2 min-1
2.42 min-1
2.06  10-3 min-1
2.40  10-2 min-1
30. The first-order reaction SO2Cl2  SO2 + Cl2 is 10% complete in 80. min. How long would it take for the
reaction to be 95% complete?
A.
B.
C.
D.
E.
1.8 min
104 min
530 min
2300 min
990 min
32. A certain reaction A  products is second order in A. If this reaction is 10.% complete after 20. s, how
long would it take for the reaction to be 90.% complete?
A.
B.
C.
D.
E.
180 s
1600 s
440 s
18,000 s
540 s
35. For the reaction X + Y  Z, the reaction rate is found to depend only upon the concentration of X. A plot
of 1/X verses time gives a straight line.
What is the rate law for this reaction?
A.
B.
C.
D.
rate = k [X]
rate = k [X]2
rate = k [X][Y]
rate = k [X]2[Y]
36. The reaction 2NO2(g)  2NO(g) + O2(g) is suspected to be second order in NO2. Which of the following
kinetic plots would be the most useful to confirm whether or not the reaction is second order?
A.
B.
C.
D.
E.
a plot of [NO2]-1 vs. t
a plot of ln [NO2] vs. t
a plot of [NO2] vs. t
a plot of ln [NO2]-1 vs. t
a plot of [NO2]2 vs. t
37. The thermal decomposition of acetaldehyde, CH3CHO  CH4 + CO, is a second-order reaction. The
following data were obtained at 518C.
Calculate the rate constant for the decomposition of acetaldehyde from the above data.
A.
B.
C.
D.
E.
2.2  10-3/s
0.70 mmHg/s
2.2  10-3/mmHg·s
6.7  10-6/mmHg·s
5.2  10-5/mmHg·s
41. The graphs below all refer to the same reaction. What is the order of this reaction?
A.
B.
C.
D.
zeroth order
first order
second order
unable to predict
43. For a second order reaction, the half-life is equal to
A.
B.
C.
D.
E.
t1/2 = 0.693/k.
t1/2 = k/0.693.
t1/2 = 1/k[A]o.
t1/2 = k.
t1/2 = [A]o/2k.
44. Which one of the following changes would alter the rate constant (k) for the reaction 2A + B  products?
A.
B.
C.
D.
increasing the concentration of A
increasing the concentration of B
increasing the temperature
measuring k again after the reaction has run for a while
45. The Arrhenius equation is k = A e-(Ea/RT). The slope of a plot of ln k vs. 1/T is equal to
A.
B.
C.
D.
E.
-k.
k.
Ea.
-Ea /R.
A.
47. The activation energy for the reaction CH3CO  CH3 + CO is 71 kJ/mol. How many times greater is the
rate constant for this reaction at 170C than at 150C?
A.
B.
C.
D.
E.
0.40
1.1
2.5
4.0
5.0
48. If Ea for a certain biological reaction is 50. kJ/mol, by what factor (how many times will the rate of this
reaction increase when body temperature increases from 37C (normal) to 40C (fever)?
A.
B.
C.
D.
E.
1.15
1.20
2.0  105
1.0002
2.0
50. At 30C, by how much is a reaction's activation energy decreased by the addition of a catalyst if the
catalyst triples the reaction rate?
A.
B.
C.
D.
E.
2.77 kJ/mol
274 J/mol
2.70 J/mol
119 J/mol
1.20 kJ/mol
52. The isomerization of cyclopropane follows first order kinetics. The rate constant at 700 K is 6.20  10-4
min-1, and the half-life at 760 K is 29.0 min. Calculate the activation energy for this reaction.
A.
B.
C.
D.
E.
5.07 kJ/mol
27.0 kJ/mol
50.7 kJ/mol
160. kJ/mol
270. kJ/mol
55. The reaction C4H10  C2H6 + C2H4 has an activation energy (Ea) of 350 kJ/mol, and the Ea of the reverse
reaction is 260 kJ/mol. Estimate H, in kJ/mol, for the reaction as written above.
A.
B.
C.
D.
E.
-90 kJ/mol
+90 kJ/mol
350 kJ/mol
-610 kJ/mol
+610 kJ/mol
58. The activation energy for the reaction O + O3  2O2 is 25 kJ/mol, and the enthalpy change is H = -388
kJ/mol. What is the activation energy for the decomposition of O2 by the reverse reaction?
A.
B.
C.
D.
E.
413 kJ
388 kJ
363 kJ
50 kJ
25 kJ
60. An increase in the temperature of the reactants causes an increase in the rate of reaction. The best
explanation for this behavior is that as the temperature increases,
A.
B.
C.
D.
E.
the concentration of reactants increases.
the activation energy decreases.
the collision frequency increases.
the fraction of collisions with total kinetic energy > Ea increases.
the activation energy increases.
63. When the concentrations of reactant molecules are increased, the rate of reaction increases. The best
explanation for this phenomenon is that as the reactant concentration increases,
A.
B.
C.
D.
E.
the average kinetic energy of molecules increases.
the frequency of molecular collisions increases.
the rate constant increases.
the activation energy increases.
the order of reaction increases.
Chapter 13 Chemical Kinetics Key
1.E
2.B
3.C
4.B
5.C
6.E
7.C
8.D
9.D
10.D
11.C
12.C
13.E
14.D
15.B
16.E
17.D
18.E
19.C
20.D
21.B
22.A
23.C
24.B
25.D
26.E
27.B
28.B
29.D
30.D
31.A
32.B
33.E
34.D
35.B
36.A
37.D
38.B
39.A
40.C
41.A
42.A
43.C
44.C
45.D
46.C
47.C
48.B
49.D
50.A
51.B
52.E
53.E
54.A
55.B
56.A
57.C
58.A
59.D
60.D
61.A
62.B
63.B