Multiple choice (only show examples)
2.What will happen to the height (h) of the column of mercury in the manometer shown below if
the stopcock is opened?
A)
B)
C)
D)
h will decrease
h will not change
h will increase
not enough information given to answer the question
Ans: A
Category: Medium
Section: 5.2
3. What will happen to the height (h) of the mercury column in the manometer shown below
if the stopcock is opened, given that the atmospheric pressure is 755 mmHg?
Page 63
Chapter 4: Reactions in Aqueous Solution
A)
B)
C)
D)
h will decrease
h will not change
h will increase
not enough information given to answer the question
Ans: A
Category: Medium
Section: 5.2
4. A pressure that will support a column of Hg to a height of 256 mm would support a
column of water to what height? The density of mercury is 13.6 g/cm3; the density of
water is 1.00 g/cm3.
2
ft
B) 18.8 mm
C) 33.8 ft
D) 76.0 cm
E) 348 cm
Ans: E
Category: Medium
Section: 5.2
5. The pressure of a gas sample was measured to be 654 mmHg. What is the pressure in
5
Pa)
4
A) 87.2 kPa D)
kPa
7
B) 118 kPa E)
kPa
4
C)
kPa
Ans: A
Category: Medium
Section: 5.2
6. The pressure of a gas sample was measured to be 489 mmHg. Which of the following is
5
not
Pa)
4
Pa
C) 489 torr
D) 0.811 atm
Ans: D
Category: Medium
Section: 5.2
7. Which of these properties is/are characteristic(s) of gases?
Page 64
Chapter 4: Reactions in Aqueous Solution
A)
B)
C)
D)
E)
8.
High compressibility
Relatively large distances between molecules
Formation of homogeneous mixtures regardless of the nature of gases
A and B.
A, B, and C.
Ans: E
Category: Easy
Section: 5.1
3
mL at 25°C and 760 mmHg. What volume will
it occupy at the same temperature and 380 mmHg?
A) 2,800 mL
B) 2,100 mL
C) 1,400 mL
D) 1,050 mL
E) 700
mL
Ans: A
Category: Medium
Section: 5.3
9. A sample of nitrogen gas has a volume of 32.4 L at 20°C. The gas is heated to 220ºC at
constant pressure. What is the final volume of nitrogen?
A) 2.94 L
B) 19.3 L
C) 31.4 L
D) 54.5 L
E) 356 L
Ans: D
Category: Medium
Section: 5.3
10. If 30.0 L of oxygen are cooled from 200ºC to 1°C at constant pressure, what is the new
volume of oxygen?
3
L
Ans: B
Category: Medium
Section: 5.3
11. A sample of N2 gas occupies 2.40 L at 20°C. If the gas is in a container that can
contract or expand at constant pressure, at what temperature will the N2 occupy 4.80 L?
A) 10°C
B) 40°C
C) 146°C
D) 313°C
E) 685°C
Ans: D
Category: Medium
Section: 5.3
12. The gas pressure in an aerosol can is 1.8 atm at 25°C. If the gas is an ideal gas, what
pressure would develop in the can if it were heated to 475°C?
A) 0.095 atm
B) 0.717 atm
C) 3.26 atm
D) 4.52 atm
E) 34.2
atm
Ans: D
Category: Medium
Section: 5.3
13. If the pressure of a gas sample is quadrupled and the absolute temperature is doubled, by
what factor does the volume of the sample change?
A) 8
B) 2
C) 1/2
D) 1/4
E) 1/8
Ans: C
Category: Medium
Section: 5.4
14. If the pressure on a gas sample is tripled and the absolute temperature is quadrupled, by
what factor will the volume of the sample change?
A) 12
B) 4/3
C) 3/4
D) 1/3
E) 4
Ans: B
Category: Medium
Section: 5.4
Page 65
Chapter 4: Reactions in Aqueous Solution
15. A small bubble rises from the bottom of a lake, where the temperature and pressure are
4°C and 3.0 atm, to the water's surface, where the temperature is 25°C and the pressure is
0.95 atm. Calculate the final volume of the bubble if its initial volume was 2.1 mL.
A) 0.72 mL
B) 6.2 mL
C) 41.4 mL
D) 22.4 mL
E) 7.1 mL
Ans: E
Category: Medium
Section: 5.4
16. The temperature of an ideal gas in a 5.00 L container originally at 1 atm pressure and
25°C is lowered to 220 K. Calculate the new pressure of the gas.
A) 1.0 atm
B) 1.35 atm
C) 8.8 atm
D) 0.738 atm
E) 0.114 atm
Ans: D
Category: Medium
Section: 5.3
17. 0.820 mole of hydrogen gas has a volume of 2.00 L at a certain temperature and pressure.
What is the volume of 0.125 mol of this gas at the same temperature and pressure?
A) 0.0512 L
B) 0.250 L
C) 0.305 L
D) 4.01 L
E) 19.5 L
Ans: C
Category: Medium
Section: 5.3
18. At what temperature will a fixed amount of gas with a volume of 175 L at 15°C and 760
mmHg occupy a volume of 198 L at a pressure of 640 mm Hg?
A) 274°C
B) 214°C
C) 114°C
D) 1°C
E) –59°C
Ans: D
Category: Medium
Section: 5.4
19. At what temperature will a fixed mass of gas with a volume of 125 L at 15°C and 750
mmHg occupy a volume of 101 L at a pressure of 645 mm Hg?
A) –73°C
B) 10.4°C
C) 2°C
D) 34°C
E) 200°C
Ans: A
Category: Medium
Section: 5.4
20. Calculate the number of moles of gas contained in a 10.0 L tank at 22°C and 105 atm. (R
–3
582 mol
Ans: D
mol
B) 0.0231 mol
Category: Medium
C)
1.03 mol
D) 43.4 mol
E)
Section: 5.4
21. Calculate the volume occupied by 35.2 g of methane gas (CH4) at 25°C and 1.0 atm. R =
A) 0.0186 L
B) 4.5 L
C) 11.2 L
D) 49.2 L
Ans: E
Category: Medium
Section: 5.4
E) 53.7 L
22. Calculate the volume occupied by 25.2 g of CO2 at 0.84 atm and 25°C. R = 0.08206
A) 0.060 L
B) 1.34 L
C) 16.9 L
D) 24.2 L
Ans: C
Category: Medium
Section: 5.4
E) 734 L
23. A gas evolved during the fermentation of sugar was collected. After purification its
volume was found to be 25.0 L at 22.5°C and 702 mmHg. How many moles of gas were
collected?
A) 0.95 mol
B) 1.05 mol
C) 12.5 mol
D) 22.4 mol
E) 724 mol
Page 66
Chapter 4: Reactions in Aqueous Solution
Ans: A
Category: Medium
Section: 5.4
24. How many molecules of N2 gas can be present in a 2.5 L flask at 50°C and 650 mmHg?
–23
25
A)
molecules D)
molecules
22
B)
molecules E) 0.081 molecules
23
C)
molecules
Ans: B
Category: Medium
Section: 5.4
25. Calculate the mass, in grams, of 2.74 L of CO gas measured at 33°C and 945 mmHg.
A) 0.263 g
B) 2.46 g
C) 3.80 g
D) 35.2 g
E) 206 g
Ans: C
Category: Medium
Section: 5.4
26. A 1.2 L flask contains 0.500 mole of ammonia (NH3) at 150°C. Calculate the pressure
of the ammonia inside the flask.
–2
atm
B) 5.13 atm
C) 12.2 atm
D) 14.5 atm
E)
22.4 atm
Ans: D
Category: Easy
Section: 5.4
27. Gases are sold in large cylinders for laboratory use. What pressure, in atmospheres, will
be exerted by 2,500 g of oxygen gas (O2) when stored at 22°C in a 40.0 L cylinder?
4
A) 3.55 atm
atm
E)
10.2 atm
Ans: C
Category: Medium
Section: 5.4
28. Calculate the density, in g/L, of CO2 gas at 27°C and 0.50 atm pressure.
A) 0.89 g/L
B) 1.12 g/L
C) 9.93 g/L
D) 46.0 g/L
E) 2.17 kg/L
Ans: A
Category: Medium
Section: 5.4
29. Calculate the density of CO2(g) at 100°C and 10.0 atm pressure.
A) 1.44 g/L
B) 134 g/L
C) 44.0 g/L
D) 53.6 g/L
Ans: E
Category: Medium
Section: 5.4
E) 14.4 g/L
30. Calculate the density of Br2(g) at 59.0°C and 1.00 atm pressure.
A) 27.2 g/L
B) 5.83 g/L
C) 769 g/L
D) 22.4 g/L
Ans: B
Category: Medium
Section: 5.4
E) 3.45 g/L
31. Calculate the density, in g/L, of SF6 gas at 27°C and 0.500 atm pressure.
–3
g/L
B) 2.96 g/L
C) 22.4 g/L
D) 32.9 g/L
3.38 kg/L
Ans: B
Category: Medium
Section: 5.4
32. Calculate the density, in g/L, of chlorine (Cl2) gas at STP.
–2
g/L
B) 46.9 g/L
C) 1.58 g/L
0.316 kg/L
Ans: D
Category: Medium
Section: 5.4
Page 67
D) 3.16 g/L
E)
E)
Chapter 4: Reactions in Aqueous Solution
33. Calculate the density of Ar(g) at –11°C and 675 mmHg.
A) 1.52 g/L
B) 1.65 g/L
C) –39.3 g/L
D) 39.95 g/L
g/L
Ans: B
Category: Medium
Section: 5.4
E) 1254
34. Which of these gases will have the greatest density at the same specified temperature and
pressure?
A) H2
B) CClF3
C) CO2
D) C2H6
E) CF4
Ans: B
Category: Medium
Section: 5.4
35. Which one of these gases is "lighter-than-air"?
A) Cl2
B) SO2
C) PH3
D) NO2
Ans: E
Category: Medium
Section: 5.4
E) Ne
36. Two moles of chlorine gas at 20.0°C are heated to 350°C while the volume is kept
constant. The density of the gas
A) increases.
B) decreases.
C) remains the same.
D) Not enough information is given to correctly answer the question.
Ans: C
Category: Medium
Section: 5.4
37. Determine the molar mass of chloroform gas if a sample weighing 0.389 g is collected in
a flask with a volume of 102 cm3 at 97°C. The pressure of the chloroform is 728
mmHg.
A) 187 g/mol
D) 31.6 g/mol
-3
B) 121 g/mol
E)
g/mol
C) 112 g/mol
Ans: B
Category: Medium
Section: 5.4
38. What is the molar mass of Freon-11 gas if its density is 6.13 g/L at STP?
A) 0.274 g/mol
B) 3.64 g/mol
C) 78.2 g/mol
D) 137 g/mol
365 g/mol
Ans: D
Category: Medium
Section: 5.4
E)
39. Determine the molar mass of Freon-11 gas if a sample weighing 0.597 g occupies 100.
cm3 at 95°C, and 1,000. mmHg.
A) 0.19 g/mol
B) 35.3 g/mol
C) 70.9 g/mol
D) 137 g/mol
E)
384 g/mol
Ans: D
Category: Medium
Section: 5.4
40. 1.018 g of Freon-113 gas is trapped in a 145 mL container at 760. mmHg and 50.0°C.
What is the molar mass of Freon-113?
A) 21.7 g/mol
B) 28.8 g/mol
C) 46.1 g/mol
D) 186 g/mol
E)
245 g/mol
Ans: D
Category: Medium
Section: 5.4
Page 68
Chapter 4: Reactions in Aqueous Solution
41. A 0.271 g sample of an unknown vapor occupies 294 mL at 140°C and 847 mmHg. The
empirical formula of the compound is CH2. What is the molecular formula of the
compound?
A) CH2
B) C2H4
C) C3H6
D) C4H8
E) C6H12
Ans: B
Category: Medium
Section: 5.4
42. A 1.17 g sample of an alkane hydrocarbon gas occupies a volume of 674 mL at 28°C and
741 mmHg. Alkanes are known to have the general formula CnH2n+2. What is the
A) CH4
Ans: C
B) C2H6
C) C3H8
D) C4H10
Category: Medium
Section: 5.4
E) C5H12
43. A 1.07 g sample of a Noble gas occupies a volume of 363 mL at 35°C and 678 mmHg.
l)
A) He
B) Ne
C) Ar
D) Kr
E) Xe
Ans: D
Category: Medium
Section: 5.4
44. A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass. A 5.25-g sample
of the gas occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at –4.0°C.
Which of these choices is its molecular formula?
A) NO
B) NO2
C) N3O6
D) N2O4
E) N2O5
Ans: D
Category: Medium
45. A mixture of three gases has a total pressure of 1,380 mmHg at 298 K. The mixture is
analyzed and is found to contain 1.27 mol CO2, 3.04 mol CO, and 1.50 mol Ar. What is
the partial pressure of Ar?
A) 0.258 atmD) 5,345 mmHg
B) 301 mmHg E) 8,020 mmHg
C) 356 mmHg
Ans: C
Category: Medium
Section: 5.6
46. A sample of hydrogen gas was collected over water at 21°C and 685 mmHg. The
volume of the container was 7.80 L. Calculate the mass of H2(g) collected. (Vapor
pressure of water = 18.6 mmHg at 21°C.)
A) 0.283 g
B) 0.572 g
C) 0.589 g
D) 7.14 g
E) 435 g
Ans: B
Category: Medium
Section: 5.6
47. A sample of carbon monoxide gas was collected in a 2.0 L flask by displacing water at
28°C and 810 mmHg. Calculate the number of CO molecules in the flask. The vapor
pressure of water at 28°C is 28.3 mmHg.
22
22
23
23
E)
25
Ans: A
Category: Medium
Section: 5.6
Page 69
Chapter 4: Reactions in Aqueous Solution
48. Air contains 78% N2, 21% O2, and 1% Ar, by volume. What is the density of air at
1,000. torr and –10°C?
A) 1.0 g/L
B) 6.1 g/L
C) 1.3 g/L
D) 1.8 g/L
E) 0.56 g/L
Ans: D
Category: Difficult
Section: 5.6
49. What volume of oxygen gas at 320 K and 680 torr will react completely with 2.50 L of
NO gas at the same temperature and pressure?
2NO(g) + O2
2(g)
A) 1.25 L
B) 2.50 L
C) 3.00 L
D) 1.00 L
E) 5.00 L
Ans: A
Category: Medium
Section: 5.5
50. 2.0 L of gas A at 1.0 atm and 1.0 L of gas B at 1.0 atm are combined in a 3 L flask. The
flask is sealed and over time they react to completely to give gas C according to the
following chemical equation:
Assuming the temperature stays constant, what will be the pressure after the reaction goes
to completion?
A) 0.33 atm
B) 0.50 atm
C) 0.67 atm
D) 0.75 atm
E) 1.0 atm
Ans: A
Category: Medium
Section: 5.6
51. Gas A and gas B are combined in a flask at initial pressures of 1.0 atm each. The flask is
sealed and over time they react to completion to give gas C according to the following
chemical equation:
Assuming the temperature stays constant, what will be the total pressure in the flask after
the reaction goes to completion?
A) 0.33 atm
B) 0.50 atm
C) 0.67 atm
D) 0.75 atm
E) 1.0 atm
Ans: E
Category: Difficult
Section: 5.6
52. What volume of CO2 gas at 645 torr and 800 K could be produced by the reaction of 45 g
of CaCO3 according to the equation?
CaCO3
2(g)
A) 0.449 L
B) 22.4 L
C) 25.0 L
D) 34.8 L
E) 45.7 mL
Ans: D
Category: Medium
Section: 5.5
53. How many liters of chlorine gas at 25°C and 0.950 atm can be produced by the reaction
of 12.0 g of MnO2 with excess HCl(aq) according to the following chemical equation?
MnO2
2(aq) + 2H2O(l) + Cl2(g)
-3
L
B) 0.138 L
C) 0.282 L
D) 3.09 L
E) 3.55 L
Ans: E
Category: Medium
Section: 5.5
54. How many liters of oxygen gas at 153°C and 0.820 atm can be produced by the
decomposition of 22.4 g of solid KClO3? (The other decomposition product is solid
potassium chloride.)
A) 3.0 L
B) 0.085 L
C) 4.20 L
D) 7.79 L
E) 11.7 L
Ans: E
Category: Difficult
Section: 5.5
Page 70
Chapter 4: Reactions in Aqueous Solution
55. When active metals such as magnesium are immersed in acid solution, hydrogen gas is
evolved. Calculate the volume of H2(g) at 30.1°C and 0.85 atm that can be formed when
275 mL of 0.725 M HCl solution reacts with excess Mg to give hydrogen gas and
aqueous magnesium chloride.
-3
L
B) 2.2 L
C) 2.9 L
D) 5.8 L
E) 11.7 L
Ans: C
Category: Difficult
Section: 5.5
56. Calculate the volume of H2(g) at 273 K and 2.00 atm that will be formed when 275 mL of
0.725 M HCl solution reacts with excess Mg to give hydrogen gas and aqueous
magnesium chloride.
A) 0.56 L
B) 1.12 L
C) 2.23 L
D) 4.47 L
E) 3.54 L
Ans: B
Category: Difficult
Section: 5.5
57. What mass of KClO3 must be decomposed to produce 126 L of oxygen gas at 133°C and
0.880 atm? (The other reaction product is solid KCl.)
A) 24.6 g
B) 70.8 g
C) 272 g
D) 408 g
E) 612 g
Ans: C
Category: Difficult
Section: 5.5
58. Liquid nitrogen has a density of 0.807 g/mL at –195.8 °C. If 1.00 L of N2(l) is allowed to
warm to 25°C at a pressure of 1.0 atm, what volume will the gas occupy? (R = 0.08206
3
Ans: C
Category: Medium
4
L
Section: 5.5
59. Which statement is false?
A) The average kinetic energies of molecules from samples of different "ideal" gases is the
same at the same temperature.
B) The molecules of an ideal gas are relatively far apart.
C) All molecules of an ideal gas have the same kinetic energy at constant temperature.
D) Molecules of a gas undergo many collisions with each other and the container walls.
E) Molecules of greater mass have a lower average speed than those of less mass at the same
temperature.
Ans: C
Category: Medium
Section: 5.7
60. The molecules of different samples of an ideal gas have the same average kinetic
energies, at the same
A) pressure.
B) temperature.
C) volume.
D) density.
Ans: B
Category: Easy
Section: 5.7
61. If equal masses of O2(g) and HBr(g) are in separate containers of equal volume and
temperature, which one of these statements is true?
A) The pressure in the O2 container is greater than that in the HBr container.
B) There are more HBr molecules than O2 molecules.
C) The average velocity of the O2 molecules is less than that of the HBr molecules.
D) The average kinetic energy of HBr molecules is greater than that of O2 molecules.
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Chapter 4: Reactions in Aqueous Solution
E) The pressures of both gases are the same.
Ans: A
Category: Medium
Section: 5.4
62. Which gas has molecules with the greatest average molecular speed at 25°C?
A) CH4
B) Kr
C) N2
D) CO2
E) Ar
Ans: A
Category: Easy
Section: 5.7
63.
A)
B)
C)
D)
E)
Which of these gas molecules have the highest average kinetic energy at 25°C?
H2
O2
N2
Cl2
All the gases have the same average kinetic energy.
Ans: E
Category: Easy
Section: 5.7
64. Deviations from the ideal gas law are greater at
A) low temperatures and low pressures.
C) high temperatures and high pressures.
B) low temperatures and high pressures. D) high temperatures and low pressures.
Ans: B
Category: Medium
Section: 5.8
65. For a substance that remains a gas under the conditions listed, deviation from the ideal
gas law would be most pronounced at
A) 100°C and 2.0 atm. D) –100°C and 4.0 atm.
B) 0°C and 2.0 atm. E) 100°C and 4.0 atm.
C) –100°C and 2.0 atm.
Ans: D
Category: Medium
Section: 5.8
66. What is the pressure of the gas trapped in the apparatus shown below when the
atmospheric pressure is 720 mmHg?
Page 72
Chapter 4: Reactions in Aqueous Solution
A) 12 mmHg
B) 708 mmHg
760 mmHg
Ans: B
Category: Medium
C) 720 mmHg
D) 732 mmHg
Section: 5.2
67. Determine the pressure of the gas trapped in the apparatus shown below when the
atmospheric pressure is 695 mmHg.
Page 73
E)
Chapter 4: Reactions in Aqueous Solution
A) 45 mmHg
B) 650 mmHg
760 mmHg
Ans: D
Category: Medium
C) 695 mmHg
D) 740 mmHg
E)
Section: 5.2
68. 10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously
evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and
water vapor, what is the final gas pressure inside the vessel at 23ºC?
A) 1.79 atm
B) 6.48 atm
C) 3.50 atm
D) 0.285 atm
E) 3.67
atm
Ans: E
Category: Difficult
Section: 5.6
69. 5.00 g of hydrogen gas and 50.0 g of oxygen gas are introduced into an otherwise empty
9.00 L steel cylinder, and the hydrogen is ignited by an electric spark. If the reaction
product is gaseous water and the temperature of the cylinder is maintained at 35ºC, what
is the final gas pressure inside the cylinder?
Page 74
Chapter 4: Reactions in Aqueous Solution
A) 7.86 atm
B) 18.3 atm
Ans: A
Category: Difficult
C) 2.58 atm
Section: 5.6
D) 6.96 atm
E) 0.92 atm
70. 9.45 g of liquid hexane (C6H14) is introduced into a 10.0 L vessel containing 13.15 atm of
oxygen gas at 21ºC and ignited, yielding carbon dioxide and water. If the vessel is then
cooled to –10ºC, what will be the gas pressure inside the vessel?
A) 3.09 atm
B) 13.15 atm
C) 1.42 atm
D) 10.9 atm
E) 12.6
atm
Ans: D
Category: Difficult
Section: 5.6
71. 10.0 g of gaseous ammonia and 6.50 g of oxygen gas are introduced into a previously
evacuated 5.50 L vessel. If the ammonia and oxygen then react to yield NO gas and
water vapor, what is the final density of the gas mixture inside the vessel at 23ºC?
A) 1.68 g/L
B) 3.00 g/L
C) 1.32 g/L
D) 2.20 g/L
E) 16.5 g/L
Ans: B
Category: Difficult
Section: 5.6
72. A method of removing CO2 from a spacecraft is to allow the CO2 to react with sodium
hydroxide. (The products of the reaction are sodium carbonate and water.) What
volume of carbon dioxide at 25°C and 749 mmHg can be removed per kilogram of
sodium hydroxide that reacts?
A) 301 L
B) 284 L
C) 276 L
D) 310 L
E) 620 L
Ans: D
Category: Difficult
Section: 5.5
73. A spacecraft is filled with 0.500 atm of N2 and 0.500 atm of O2. Suppose a micrometeor
strikes this spacecraft and puts a very small hole in it's side. Under these circumstances,
A) O2 is lost from the craft 6.9% faster than N2 is lost.
B) O2 is lost from the craft 14% faster than N2 is lost.
C) N2 is lost from the craft 6.9% faster than O2 is lost.
D) N2 is lost from the craft 14% faster than O2 is lost.
E) N2 and O2 are lost from the craft at the same rate.
Ans: C
Category: Medium
Section: 5.7
74. A spacecraft is filled with 0.500 atm of O2 and 0.500 atm of He. If there is a very small
hole in the side of this craft such that gas is lost slowly into outer space,
A) He is lost 2.8 times faster than O2 is lost.
B) He is lost 8 times faster than O2 is lost.
C) He is lost twice as fast as O2 is lost.
D) O2 is lost 2.8 times faster than He is lost.
E) O2 is lost 8 times faster than He is lost.
Ans: A
Category: Medium
Section: 5.7
75. 1.000 atm of dry nitrogen, placed in a container having a pinhole opening in its side,
leaks from the container 3.55 times faster than does 1.000 atm of an unknown gas placed
in this same apparatus. Which of these species could be the unknown gas?
A) NH3
B) C4H10
C) SF6
D) UF6
E) Rn
Ans: D
Category: Medium
Section: 5.7
Page 75
Chapter 4: Reactions in Aqueous Solution
76. 1.000 atm of oxygen gas, placed in a container having a pinhole opening in its side, leaks
from the container 2.14 times faster than does 1.000 atm of an unknown gas placed in this
same apparatus. Which of these species could be the unknown gas?
A) Cl2
B) SF6
C) Kr
D) UF6
E) Xe
Ans: B
Category: Medium
Section: 5.7
77. Samples of the following volatile liquids are opened simultaneously at one end of a room.
If you are standing at the opposite end of this room, which species would you smell first?
(Assume that your nose is equally sensitive to all these species.)
A) ethyl acetate (CH3COOC2H5) D) naphthalene (C10H8)
B) camphor (C10H16O) E) pentanethiol (C5H11SH)
C) diethyl ether (C2H5OC2H5)
Ans: C
Category: Medium
Section: 5.7
78. A sample of mercury(II) oxide is placed in a 5.00 L evacuated container and heated until
it decomposes entirely to mercury metal and oxygen gas. The container is then cooled
to 25°C. One now finds that the gas pressure inside the container is 1.73 atm. What
mass of mercury(II) oxide was originally placed into the container?
A) 913 g
B) 76.6 g
C) 1.51 g
D) 45.6 g
E) 153 g
Ans: E
Category: Difficult
Section: 5.5
79. The mole fraction of oxygen molecules in dry air is 0.2095. What volume of dry air at
1.00 atm and 25°C is required for burning 1.00 L of hexane (C6H14, density = 0.660
g/mL) completely, yielding carbon dioxide and water?
A) 187 L
B) 712 L
C) 1780 L
D) 894 L
E) 8490
Ans: E
Category: Difficult
Section: 5.5
80. The mole fraction of oxygen molecules in dry air is 0.2095. What volume of dry air at
1.00 atm and 25°C is required for burning 1.00 L of octane (C8H18, density = 0.7025
g/mL) completely, yielding carbon dioxide and water?
A) 718 L
B) 367 L
C) 8980 L
D) 1880 L
E) 150 L
Ans: C
Category: Difficult
Section: 5.5
81. A block of dry ice (solid CO2
25.0 cm is left to sublime (i.e. to pass from the solid phase to the gas phase) in a closed
dioxide in this chamber at 25°C will be
A) 171 mmHg D) 0.171 mmHg
B) 107 mmHg E) 14.4 mmHg
C) 0.225 mmHg
Ans: A
Category: Medium
Section: 5.5
Page 76
Chapter 4: Reactions in Aqueous Solution
82. A 2.50-L flask contains a mixture of methane (CH4) and propane (C3H8) at a pressure of
1.45 atm and 20°C. When this gas mixture is then burned in excess oxygen, 8.60 g of
carbon dioxide is formed. (The other product is water.) What is the mole fraction of
methane in the original gas mixture?
A) 0.341
B) 1.00
C) 0.659
D) 0.855
E) 0.145
Ans: D
Category: Difficult
Section: 5.7
7.An exothermic reaction causes the surroundings to
A) warm up.
D) decrease its temperature.
B) become acidic.
E) release CO2.
C) expand.
Ans: A
Category: Easy
Section: 6.2
8. Copper metal has a specific heat of 0.385 J/g·°C. Calculate the amount of heat required to
raise the temperature of 22.8 g of Cu from 20.0°C to 875°C.
A) 1.97  10–5 J
B) 1.0  10–2 J
C) 329 J
D) 7.51 kJ
E) 10.5 kJ
Ans: D
Category: Medium
Section: 6.5
9. Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from
15.4°C to 93.0°C. The specific heat of water = 4.18 J/g·°C.
A) 0.027 J
B) 324 J
C) 389 J
D) 931 J
E) 3,890 J
Ans: E
Category: Medium
Section: 6.5
10. How much heat is required to raise the temperature of 2,500 g of water from 27°C to
72°C? The specific heat of water is 4.184 J/g·°C.
A) 0.19 kJ
B) 10. kJ
C) 280 kJ
D) 470 kJ
E) 750 kJ
Ans: D
Category: Medium
Section: 6.5
11. A beaker contains 115 g of ethanol at 18.2°C. If the ethanol absorbs 1125 J of heat
without losing heat to the surroundings, what will be the final temperature of the ethanol?
The specific heat of ethanol is 2.46 J/g°C.
A) 4.08°C
B) 14.1°C
C) 18.4°C
D) 22.2°C
E) 36.4°C
Ans: D
Category: Medium
Section: 6.5
12. How many degrees of temperature rise will occur when a 25.0 g block of aluminum
absorbs 10.0 kJ of heat? The specific heat of Al is 0.900 J/g·°C.
A) 0.44°C
B) 22.5°C
C) 225°C
D) 360°C
E) 444°C
Ans: E
Category: Medium
Section: 6.5
13. If 325 g of water at 4.2°C absorbs 12.28 kJ, what is the final temperature of the water?
The specific heat of water is 4.184 J/g·°C.
A) 4.21°C
B) 4.8°C
C) 9.0°C
D) 13.2°C
E) 2,938°C
Ans: D
Category: Medium
Section: 6.5
Page 77
Chapter 4: Reactions in Aqueous Solution
14. A glass containing 200. g of H2O at 20°C was placed in a refrigerator. The water loses
11.7 kJ as it cools to a constant temperature. What is its new temperature? The specific
heat of water is 4.184 J/g·°C.
A) 0.013°C
B) 4°C
C) 6°C
D) 14°C
E) 34°C
Ans: C
Category: Medium
Section: 6.5
15. A piece of copper with a mass of 218 g has a heat capacity of 83.9 J/°C. What is the
specific heat of copper?
A) 0.385 J/g·°C
D) 1.32 J/g·°C
B) 1.83  104 J/g·°C
E) 24.5 J/g·°C
C) 2.60 J/g·°C
Ans: A
Category: Easy
Section: 6.5
16. The specific heat of gold is 0.129 J/g·°C. What is the molar heat capacity of gold?
A) 0.039 J/mol·°C
D) 39.0 kJ/mol·°C
B) 0.129 J/mol·°C
E) 197 J/mol·°C
C) 25.4 J/mol·°C
Ans: C
Category: Easy
Section: 6.5
17. Suppose a 50.0 g block of silver (specific heat = 0.2350 J/g·°C) at 100°C is placed in
contact with a 50.0 g block of iron (specific heat = 0.4494 J/g·°C) at 0°C, and the two
blocks are insulated from the rest of the universe. The final temperature of the two
blocks
A) will be higher than 50°C.
B) will be lower than 50°C.
C) will be exactly 50°C.
D) is unrelated to the composition of the blocks.
E) cannot be predicted.
Ans: B
Category: Medium
Section: 6.5
18. When 0.7521 g of benzoic acid was burned in a calorimeter containing 1,000. g of water,
a temperature rise of 3.60°C was observed. What is the heat capacity of the bomb
calorimeter, excluding the water? The heat of combustion of benzoic acid is –26.42
kJ/g.
A) 15.87 kJ/°C
D) 1.34 kJ/°C
B) 4.18 kJ/°C
E) 752.1 kJ/°C
C) 5.52 kJ/°C
Ans: D
Category: Medium
Section: 6.5
Page 78
Chapter 4: Reactions in Aqueous Solution
19. Naphthalene combustion can be used to calibrate the heat capacity of a bomb calorimeter.
The heat of combustion of naphthalene is –40.1 kJ/g. When 0.8210 g of naphthalene
was burned in a calorimeter containing 1,000. g of water, a temperature rise of 4.21°C
was observed. What is the heat capacity of the bomb calorimeter excluding the water?
A) 32.9 kJ/°C
B) 7.8 kJ/°C
C) 3.64 kJ/°C
D) 1.76 kJ/°C
E)
15.3 kJ/°C
Ans: C
Category: Medium
Section: 6.5
20. Which of the following processes is endothermic?
A) O2(g) + 2H2(g)  2H2O(g)
B) H2O(g)  H2O(l)
C) 3O2(g) + 2CH3OH(g)  2CO2(g) + 2H2O(g)
D) H2O(s)  H2O(l)
Ans: D
Category: Medium
Section: 6.4
21. A 100. mL sample of 0.200 M aqueous hydrochloric acid is added to 100. mL of 0.200 M
aqueous ammonia in a calorimeter whose heat capacity (excluding any water) is 480. J/K.
The following reaction occurs when the two solutions are mixed.
HCl(aq) + NH3(aq)  NH4Cl(aq)
The temperature increase is 2.34°C. Calculate H per mole of HCl and NH3 reacted.
A) 154 kJ/mol
D) –1.96 kJ/mol
B) 1.96 kJ/mol
E) –154 kJ/mol
C) 485 kJ/mol
Ans: E
Category: Difficult
Section: 6.5
22. A 0.1326 g sample of magnesium was burned in an oxygen bomb calorimeter. The total
heat capacity of the calorimeter plus water was 5,760 J/°C. If the temperature rise of the
calorimeter with water was 0.570°C, calculate the enthalpy of combustion of magnesium.
Mg(s) + 1/2O2(g)  MgO(s)
A) –3280 kJ/mol
D) 106 kJ/mol
B) –24.8 kJ/mol
E) –602 kJ/mol
C) 435 kJ/mol
Ans: E
Category: Difficult
Section: 6.5
23. To which one of the following reactions occurring at 25°C does the symbol
H°f[H2SO4(l)] refer?
A) 2H(g) + S(g) + 4O(g)  H2SO4(l)
D) H2SO4(l)  2H(g) + S(s) + 4O(g)
B) H2(g) + S(g) + 2O2(g)  H2SO4(l)
E) H2(g) + S(s) + 2O2(g)  H2SO4(l)
C) H2SO4(l)  H2(g) + S(s) + 2O2(g)
Ans: E
Category: Medium
Section: 6.6
Page 79
Chapter 4: Reactions in Aqueous Solution
24. To which one of the following reactions occurring at 25°C does the symbol
H°f[HNO3(l)] refer?
A) H(g) + N(g) + O3(g)  HNO3(l)
B) (1/2)H2(g) + (1/2)N2(g) + (3/2)O2(g)  HNO3(l)
C) HNO3(l)  (1/2)H2(g) + (1/2)N2(g) + (3/2)O2(g)
D) HNO3(l)  H(g) + N(g) + 3O(g)
E) H2(g) + N2(g) + O3(g)  HNO3(l)
Ans: B
Category: Medium
Section: 6.6
25. When 0.560 g of Na(s) reacts with excess F2(g) to form NaF(s), 13.8 kJ of heat is evolved
at standard-state conditions. What is the standard enthalpy of formation (H°f) of
NaF(s)?
A) 24.8 kJ/mol
D) –7.8 kJ/mol
B) 570 kJ/mol
E) -570 kJ/mol
C) –24.8 kJ/mol
Ans: E
Category: Medium
Section: 6.6
26. When 18.5 g of HgO(s) is decomposed to form Hg(l) and O2(g), 7.75 kJ of heat is
absorbed at standard-state conditions. What is the standard enthalpy of formation
(H°f) of HgO(s)?
A) –90.7 kJ/mol
D) 27.9 kJ/mol
B) –7.75 kJ/mol
E) 143 kJ/mol
C) 0.419 kJ/mol
Ans: A
Category: Medium
Section: 6.6
27. Ethanol undergoes combustion in oxygen to produce carbon dioxide gas and liquid water.
The standard heat of combustion of ethanol, C2H5OH(l), is –1366.8 kJ/mol. Given that
H°f[CO2(g)] = –393.5 kJ/mol and H°f[H2O(l)] = –285.8 kJ/mol, what is the standard
enthalpy of formation of ethanol?
A) 3,010 kJ/mol
D) 687.6 kJ/mol
B) –687.6 kJ/mol
E) 1,367 kJ/mol
C) –277.6 kJ/mol
Ans: C
Category: Difficult
Section: 6.6
28. Find the standard enthalpy of formation of ethylene, C2H4(g), given the following data:
heat of combustion of C2H4(g) = –1411 kJ/mol; H°f[CO2(g)] = –393.5 kJ/mol;
H°f[H2O(l)] = –285.8 kJ/mol.
A) 52 kJ/mol
D) 1.41  103 kJ/mol
B) 87 kJ/mol
E) 2.77  103 kJ/mol
C) 731 kJ/mol
Ans: A
Category: Difficult
Section: 6.6
Page 80
Chapter 4: Reactions in Aqueous Solution
29. Octane (C8H18) undergoes combustion according to the following thermochemical
equation:
2C8H18(l) + 25O2(g)  16CO2(g) + 18H2O(l)
H°rxn = –11,020 kJ/mol.
Given that H°f[CO2(g)] = –393.5 kJ/mol and H°f[H2O(l)] = –285.8 kJ/mol, calculate
the standard enthalpy of formation of octane.
A) –210 kJ/mol
D) –420 kJ/mol
B) –11,230 kJ/mol
E) 420 kJ/mol
C) 22,040 kJ/mol
Ans: A
Category: Medium
Section: 6.6
30. Glycine, C2H5O2N, is important for biological energy. The combustion reaction of
glycine is given by the equation
4C2H5O2N(s) + 9O2(g)  8CO2(g) + 10H2O(l) + 2N2(g)
H°rxn = –3857 kJ/mol
Given that H°f[CO2(g)] = –393.5 kJ/mol and H°f[H2O(l)] = –285.8 kJ/mol, calculate
the enthalpy of formation of glycine.
A) –537.2 kJ/mol
D) –3,178 kJ/mol
B) –268.2 kJ/mol
E) –964 kJ/mol
C) 2,149 kJ/mol
Ans: A
Category: Medium
Section: 6.6
31. Styrene, C8H8, is one of the substances used in the production of synthetic rubber.
When styrene burns in oxygen to form carbon dioxide and liquid water under standardstate conditions at 25°C, 42.62 kJ are released per gram of styrene. Find the standard
enthalpy of formation of styrene at 25°C.
(Given: H°f[CO2(g)] = –393.5 kJ/mol, H°f[H2O(l)] = –285.8 kJ/mol, H°f[H2O(g)] =
–241.8 kJ/mol)
A) 323.8 kJ/mol
D) ~636.7 kJ/mol
B) ~4249 kJ/mol
E) 147.8 kJ/mol
C) ~8730 kJ/mol
Ans: E
Category: Difficult
Section: 6.6
32. Given 2Al(s) + (3/2)O2(g)  Al2O3(s), H°f = –1,670 kJ/mol for Al2O3 (s).
Determine H° for the reaction 2Al2O3(s)  4Al(s) + 3O2(g).
A) 3,340 kJ/mol
D) –1,670 kJ/mol
B) 1,670 kJ/mol
E) –835 kJ/mol
C) –3,340 kJ/mol
Ans: A
Category: Easy
Section: 6.6
Page 81
Chapter 4: Reactions in Aqueous Solution
33. Calculate the standard enthalpy of formation of liquid methanol, CH3OH(l), using the
following information:
C(graph) + O2  CO2(g)
H° = –393.5 kJ/mol
H2(g) + (1/2)O2  H2O(l)
H° = –285.8 kJ/mol
CH3OH(l) + (3/2)O2(g)  CO2(g) + 2H2O(l)
H° = –726.4 kJ/mol
A)
B)
C)
Ans:
–1,691.5 kJ/mol
–238.7 kJ/mol
1691.5 kJ/mol
B
Category: Difficult
D)
E)
47.1 kJ/mol
–47.1 kJ/mol
Section: 6.6
34. Calculate the standard enthalpy change for the reaction
2C8H18(l) + 17O2(g)  16CO(g) + 18H2O(l).
Given:
2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(l)
H° = –11,020 kJ/mol
2CO(g) + O2(g)  2CO2(g)
H° = –566.0 kJ/mol
A) 10,450 kJ/mol
D) –6,492 kJ/mol
B) 6,492 kJ/mol
E) –10.450 kJ/mol
C) 15,550 kJ/mol
Ans: D
Category: Medium
Section: 6.6
35. During volcanic eruptions, hydrogen sulfide gas is given off and oxidized by air
according to the following chemical equation:
2H2S(g) + 3O2(g)  2SO2(g) + 2H2O(g)
Calculate the standard enthalpy change for the above reaction given:
3S(s) + 2H2O(g)  2H2S(g) + SO2(g)
H° = 146.9 kJ/mol
S(s) + O2(g)  SO2(g)
H° = –296.4 kJ/mol
A)
B)
C)
Ans:
–1036.1 kJ/mol
–742.3 kJ/mol
–149.5 kJ/mol
A
Category: Medium
D)
E)
443.3 kJ/mol
742.3 kJ/mol
Section: 6.6
36. Calculate the standard enthalpy change for the reaction
2C8H18(l) + 21O2(g)  8CO(g) + 8CO2(g) + 18H2O(l).
Given:
2C8H18(l) + 25O2(g)  16CO2(g) + 18H2O(l)
H° = –11,020 kJ/mol
2CO(g) + O2(g)  2CO2(g)
H° = –566.0
kJ/mol
A) 1.0454  104 kJ/mol
D) –6,492 kJ/mol
B) –8,756 kJ/mol
E) –1.0454  104 kJ/mol
4
C) 1.1586  10 kJ/mol
Ans: B
Category: Medium
Section: 6.6
Page 82
Chapter 4: Reactions in Aqueous Solution
37. Given the thermochemical equation 2SO2 + O2  2SO3, H°rxn = –198 kJ/mol,
what is the standard enthalpy change for the decomposition of one mole of SO3?
A) 198 kJ/mol
D) 396 kJ/mol
B) –99 kJ/mol
E) –198 kJ/mol
C) 99 kJ/mol
Ans: C
Category: Medium
Section: 6.6
38. Given H2(g) + (1/2)O2(g)  H2O(l), H° = –286 kJ/mol, determine the standard enthalpy
change for the reaction 2H2O(l)  2H2(g) + O2(g).
A) H° = –286 kJ/mol
D) H° = +572 kJ/mol
B) H° = +286 kJ/mol
E) H° = –143 kJ/mol
C) H° = –572 kJ/mol
Ans: D
Category: Easy
Section: 6.6
39. Pentaborane B5H9(s) burns vigorously in O2 to give B2O3(s) and H2O(l). Calculate H°rxn
for the combustion of 1 mol of B5H9.
H°f[B2O3(s)] = –1,273.5 kJ/mol
H°f[B5H9(s)] = 73.2 kJ/mol
H°f[H2O(l)] = –285.8 kJ/mol
A) –1,2735 kJ/mol
D) –9,086 kJ/mol
B) –4,543 kJ/mol
E) –8,448 kJ/mol
C) –18,170 kJ/mol
Ans: B
Category: Difficult
Section: 6.6
40. For the reaction
C(graphite) + O2(g)  CO2(g)
H° = –393 kJ/mol
how many grams of C(graphite) must be burned to release 275 kJ of heat?
A) 22.3 g
B) 0.70 g
C) 12.0 g
D) 17.1 g
E) 8.40 g
Ans: E
Category: Medium
Section: 6.4
41. The combustion of butane produces heat according to the equation
2C4H10(g) + 13O2(g)  8CO2(g) + 10H2O(l)
H°rxn = –5,314 kJ/mol
What is the heat of combustion per gram of butane?
A) –32.5 kJ/g
D) –2,656 kJ/g
B) –45.7 kJ/g
E) –15,440 kJ/g
C) –91.5 kJ/g
Ans: B
Category: Medium
Section: 6.4
Page 83
Chapter 4: Reactions in Aqueous Solution
42. The combustion of octane produces heat according to the equation
2C8H18(l) + 25O2(g)  16CO2(g) + 18H2O(l)
H°rxn= –11,020 kJ/mol
What is the heat of combustion per gram of octane?
A) –5,510 kJ/g
D) –193 kJ/g
B) –96.5 kJ/g
E) –6.292  105 kJ/g
C) –48.2 kJ/g
Ans: C
Category: Medium
Section: 6.4
43. The combustion of butane produces heat according to the equation
2C4H10(g) + 13O2(g)  8CO2(g) + 10H2O(l)
H°rxn= –5,314 kJ/mol
How many grams of butane must be burned to release 1.00  104 kJ of heat?
A) 30.9 g
B) 61.8 g
C) 109 g
D) 153 g
E) 219 g
Ans: E
Category: Medium
Section: 6.4
44. The combustion of butane produces heat according to the equation
2C4H10(g) + 13O2(g)  8CO2(g) + 10H2O(l)
H°rxn= –5,314 kJ/mol
How many grams of CO2 are produced per 1.00  104 kJ of heat released?
A) 23.4 g
B) 44.0 g
C) 82.3 g
D) 187 g
E) 662 g
Ans: E
Category: Medium
Section: 6.4
45. Given that CaO(s) + H2O(l)  Ca(OH)2(s), H°rxn = –64.8 kJ/mol, how many grams of
CaO must react in order to liberate 525 kJ of heat?
A) 6.92 g
B) 56.1 g
C) 455 g
D) 606 g
E) 3.40  104 g
Ans: C
Category: Medium
Section: 6.4
46. The combustion of pentane produces heat according to the equation
C5H12(l) + 8O2(g)  5CO2(g) + 6H2O(l)
H°rxn= –3,510 kJ/mol
How many grams of CO2 are produced per 2.50  103 kJ of heat released?
A) 0.0809 g
B) 3.56 g
C) 31.3 g
D) 157 g
E) 309 g
Ans: D
Category: Medium
Section: 6.4
47. An average home in Colorado requires 20. GJ of heat per month. How many grams of
natural gas (methane) must be burned to supply this energy?
CH4(g) + 2O2(g)  CO2(g) + 2H2O(l)
H°rxn= –890.4 kJ/mol
A) 1.4  103 g
D) 2.2  104 g
B) 3.6  105 g
E) 1.4  104 g
–4
C) 7.1  10 g
Ans: B
Category: Medium
Section: 6.4
Page 84
Chapter 4: Reactions in Aqueous Solution
48. Given the thermochemical equation 2SO2(g) + O2(g)  2SO3(g), H°rxn= –198 kJ/mol,
how much heat is evolved when 600. g of SO2 is burned?
A) 5.46  10–2 kJ
D) 59,400 kJ
B) 928 kJ
E) 3.71  103 kJ
C) 1.85  103 kJ
Ans: B
Category: Medium
Section: 6.4
49. Determine the heat given off to the surroundings when 9.0 g of aluminum reacts
according to the equation 2Al + Fe2O3  Al2O3 + 2Fe, H°rxn= –849 kJ/mol.
A) 7.6  103 kJ
D) 5.6  102 kJ
B) 2.8  102 kJ
E) 2.5  103 kJ
C) 1.4  102 kJ
Ans: C
Category: Medium
Section: 6.4
50. Find the heat absorbed from the surroundings when 15 g of O2 reacts according to the
equation O + O2  O3, H°rxn= –103 kJ/mol.
A) 4.6  10–3 kJ
B) 48 kJ
C) 96 kJ
D) 32 kJ
E) 110 kJ
Ans: B
Category: Medium
Section: 6.4
51. Ethanol (C2H5OH) burns according to the equation
C2H5OH(l) + 3O2(g)  2CO2(g) + 3H2O(l), H°rxn = –1367 kJ/mol.
How much heat is released when 35.0 g of ethanol is burned?
A) 1,797 kJ
B) 1,367 kJ
C) 9.61  10–4 kJ
D) 4.78  104 kJ
1,040 kJ
Ans: E
Category: Medium
Section: 6.4
E)
52. Methanol (CH3OH) burns according to the equation
2CH3OH(l) + 3O2(g)  2CO2(g) + 4H2O(l), H°rxn = –1454 kJ/mol.
How much heat, in kilojoules, is given off when 75.0 g of methanol is burned?
A) 727 kJ
D) 1.70  10–3 kJ
B) 3.22  103 kJ
E) 3.41  103 kJ
C) 1.45  103 kJ
Ans: D
Category: Medium
Section: 6.4
53. Calcium oxide and water react in an exothermic reaction:
CaO(s) + H2O(l)  Ca(OH)2(s)
H°rxn = –64.8 kJ/mol
How much heat would be liberated when 7.15 g CaO(s) is dropped into a beaker
containing 152g H2O?
A) 1.97  10–3 kJ
B) 8.26 kJ
C) 508 kJ
D) 547 kJ
E) 555 kJ
Ans: B
Category: Medium
Section: 6.4
Page 85
Chapter 4: Reactions in Aqueous Solution
54. Solid sodium peroxide (Na2O2) reacts with liquid water yielding aqueous sodium
hydroxide and oxygen gas. How much heat is released when 250.0 L of oxygen gas is
produced from the reaction of sodium peroxide and water if the reaction is carried out in
an open container at 1.000 atm pressure and 25°C?
(Given: H°f[Na2O2(s)] = –510.9 kJ/mol; H°f[NaOH(aq)] = –469.2 kJ/mol;
H°f[H2O(l)] = –285.8 kJ/mol)
A) 35,400 kJ
B) 1740 kJ
C) 141.7 kJ
D) 3330 kJ
E) 2900 kJ
Ans: E
Category: Difficult
Section: 6.6
55. At 25°C, the standard enthalpy of formation of KCl(s) is –435.87 kJ/mol. When one
mole of KCl(s) is formed by reacting potassium vapor and chlorine gas at 25°C, the
standard enthalpy of reaction is –525.86 kJ/mol. Find H° for the sublimation of
potassium, K(s)  K(g), at 25°C.
A) –345.88 kJ/mol
D) 89.99 kJ/mol
B) 45.00 kJ/mol
E) –525.86 kJ/mol
C) 345.88 kJ/mol
Ans: D
Category: Medium
Section: 6.6
56. At 25°C, the standard enthalpy of formation of anhydrous sodium carbonate is –1130.9
kJ/mol, whereas the standard enthalpy of formation of sodium carbonate monohydrate is
–1430.1 kJ/mol. Determine H° at 25°C for the reaction
Na2CO3(s) + H2O(l)  Na2CO3·H2O(s).
(Given: H°f[H2O(l)] = –285.8 kJ/mol)
A) –13.4 kJ/mol
D) –299.2 kJ/mol
B) –285.8 kJ/mol
E) –156.3 kJ/mol
C) –585.0 kJ/mol
Ans: A
Category: Medium
Section: 6.6
57. According to the first law of thermodynamics:
A) Energy is neither lost nor gained in any energy transformations.
B) Perpetual motion is possible.
C) Energy is conserved in quality but not in quantity.
D) Energy is being created as time passes. We have more energy in the universe now
than when time began.
Ans: A
Category: Easy
Section: 6.3
58. The heat of solution of KCl is 17.2 kJ/mol and the lattice energy of KCl(s) is 701.2
kJ/mol. Calculate the total heat of hydration of 1 mol of gas phase K+ ions and Cl– ions.
A) 718 kJ
B) 684 kJ
C) –684 kJ
D) –718 kJ
E) None of these.
Ans: C
Category: Medium
Section: 6.7
59. The heat of solution of LiCl is –37.1 kJ/mol, and the lattice energy of LiCl(s) is 828
kJ/mol. Calculate the total heat of hydration of 1 mol of gas phase Li+ ions and Cl– ions.
A) 791 kJ
B) 865 kJ
C) –865 kJ
D) –791 kJ
E) None of these.
Ans: C
Category: Medium
Section: 6.7
Page 86
Chapter 4: Reactions in Aqueous Solution
60. The total heat of hydration of 1 mol of gas phase Li+ ions and Cl – ions is –865 kJ. The
lattice energy of LiCl(s) is 828 kJ/mol. Calculate the heat of solution of LiCl.
A) 37 kJ/mol
D) –37 kJ/mol
B) 1,693 kJ/mol
E) None of these.
C) –1,693 kJ/mol
Ans: D
Category: Medium
Section: 6.7
61. 10.1 g CaO is dropped into a styrofoam coffee cup containing 157 g H2O at 18.0°C.
If the following reaction occurs, then what temperature will the water reach, assuming
that the cup is a perfect insulator and that the cup absorbs only a negligible amount of
heat? (the specific heat of water = 4.18 J/g·°C)
CaO(s) + H2O(l)  Ca(OH)2(s)
H°rxn = –64.8 kJ/mol
A) 18.02°C
B) 35.8°C
C) 311°C
D) 42.2°C
E) 117°C
Ans: B
Category: Medium
Section: 6.5
62. The enthalpy change when a strong acid is neutralized by strong base is –56.1 kJ/mol.
If 135 mL of 0.450 M HI at 23.15°C is mixed with 145 mL of 0.500 M NaOH, also at
23.15°C, what will the maximum temperature reached by the resulting solution? (Assume
that there is no heat loss to the container, that the specific heat of the final solution is 4.18
J/g·°C, and that the density of the final solution is that of water.)
A) 26.06°C
B) 29.19°C
C) 32.35°C
D) 20.24°C
E) 36.57°C
Ans: A
Category: Difficult
Section: 6.5
63. The enthalpy change when a strong acid is neutralized by strong base is –56.1 kJ/mol.
If 12.0 mL of 6.00 M HBr at 21.30°C is mixed with 300. mL of 0.250 M NaOH, also at
21.30°C, what will the maximum temperature reached by the resulting solution? (Assume
that there is no heat loss to the container, that the specific heat of the final solution is 4.18
J/g·°C, and that the density of the final solution is that of water.)
A) 18.20°C
B) 24.53°C
C) 101.8°C
D) 24.40°C
E) 34.25°C
Ans: D
Category: Difficult
Section: 6.5
64. Calculate the amount of work done, in joules, when 2.5 mole of H2O vaporizes at 1.0 atm
and 25°C. Assume the volume of liquid H2O is negligible compared to that of vapor. (1
L·atm = 101.3 J)
A) 6,190 kJ
B) 6.19 kJ
C) 61.1 J
D) 5.66 kJ
E) 518 J
Ans: B
Category: Medium
Section: 6.3
65. A gas is compressed in a cylinder from a volume of 20.0 L to 2.0 L by a constant
pressure of 10.0 atm. Calculate the amount of work done on the system.
A) 1.01  104 J
B) –180 J
C) 1.81  104 J
D) –1.81  104 J
180 J
Ans: C
Category: Medium
Section: 6.3
Page 87
E)
Chapter 4: Reactions in Aqueous Solution
66. Calculate the amount of work done against an atmospheric pressure of 1.00 atm when
500.0 g of zinc dissolves in excess acid at 30.0°C.
Zn(s) + 2H+(aq)  Zn2+(aq) + H2(g)
A) w = +22.4 kJ
D) w = –2.52 kJ
B) w = +24.9 kJ
E) w = –19.3 kJ
C) w = 0
Ans: E
Category: Medium
Section: 6.3
67. A gas is allowed to expand, at constant temperature, from a volume of 1.0 L to 10.1 L
against an external pressure of 0.50 atm. If the gas absorbs 250 J of heat from the
surroundings, what are the values of q, w, and E?
Ans: A
Category: Medium
Section: 6.3
68. Which of the following processes always results in an increase in the energy of a system?
A) The system loses heat and does work on the surroundings.
B) The system gains heat and does work on the surroundings.
C) The system loses heat and has work done on it by the surroundings.
D) The system gains heat and has work done on it by the surroundings.
E) None of these is always true.
Ans: D
Category: Medium
Section: 6.3
69. For which of these reactions will the difference between H° and E° be the greatest?
A) 2H2O2(l)  2H2O(l) + O2(g)
B) CaCO3(s)  CaO(s) +CO2(g)
C) NO(g) + O3(g)  NO2(g) + O2(g)
D) 2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(l)
E) 4NH3(g) + 5O2(g)  4NO(g) + 6H2O(g)
Ans: D
Category: Medium
Section: 6.4
70. For which of these reactions will the difference between H° and E° be the smallest?
A) N2(g) + 3H2(g)  2NH3(g)
B) 4PH3(g)  P4(g) + 6H2(g)
C) H2(g) + Cl2(g)  2HCl(g)
D) CO2(g) + 2H2O(l)  CH4(g) + 2O2(g)
E) P4(s) + 10Cl2(g)  4PCl5(s)
Ans: C
Category: Medium
Section: 6.4
Page 88
Chapter 4: Reactions in Aqueous Solution
71. At 25°C, the following heats of reaction are known:
2ClF(g) + O2(g)  Cl2O(g) + F2O(g)
H°rxn = 167.4 kJ/mol
2ClF3(g) + 2O2(g)  Cl2O(g) + 3F2O(g)
H°rxn = 341.4 kJ/mol
2F2(g) + O2(g)  2F2O(g)
H°rxn = –43.4 kJ/mol
At the same temperature, use Hess's law to calculate H°rxn for the reaction:
ClF(g) + F2(g)  ClF3(g)
A) –217.5 kJ/mol
D) –108.7 kJ/mol
B) –130.2 kJ/mol
E) 465.4 kJ/mol
C) 217.5 kJ/mol
Ans: D
Category: Medium
Section: 6.6
72. The bond enthalpy of the Br–Cl bond is equal to H° for the reaction
BrCl(g)  Br(g) + Cl(g).
Use the following data to find the bond enthalpy of the Br–Cl bond.
Br2(l)  Br2(g)
H° = 30.91 kJ/mol
Br2(g)  2Br(g)
H° = 192.9 kJ/mol
Cl2(g)  2Cl(g)
H° = 243.4 kJ/mol
Br2(l) + Cl2(g)  2BrCl(g) H° = 29.2 kJ/mol
A)
B)
C)
Ans:
219.0 kJ/mol
203.5 kJ/mol
14.6 kJ/mol
A
Category: Medium
D)
E)
438.0 kJ/mol
407.0 kJ/mol
Section: 6.6
73. The heat of solution of ammonium nitrate is 26.2 kJ/mol. If a 5.368 g sample of
NH4NO3 is added to 40.0 mL of water in a calorimeter at 23.5°C, what is the minimum
temperature reached by the solution? (The specific heat of water = 4.18 J/g·°C; the heat
capacity of the calorimeter = 650. J/°C.)
A) 14.3°C
B) 20.8°C
C) –7.7°C
D) 25.6°C
E) 21.4°C
Ans: E
Category: Difficult
Section: 6.5
74. The heat of solution of ammonium chloride is 15.2 kJ/mol. If a 6.134 g sample of
NH4Cl is added to 65.0 mL of water in a calorimeter at 24.5°C, what is the minimum
temperature reached by the solution? (The specific heat of water = 4.18 J/g·°C; the heat
capacity of the calorimeter = 365. J/°C.)
A) 27.1°C
B) 18.6°C
C) 19.7°C
D) 21.9°C
E) 30.4°C
Ans: D
Category: Difficult
Section: 6.5
Page 89
Chapter 4: Reactions in Aqueous Solution
75. Aluminum oxide can be reduced to aluminum metal using carbon, the other reaction
product being carbon monoxide. Determine the enthalpy change when 12.5 g of
aluminum is produced by this method. [H°f(carbon monoxide) = –110.5 kJ/mol;
H°f(aluminum oxide) = –1669.8 kJ/mol]
A) 725 kJ
B) 697 kJ
C) 310 kJ
D) 361 kJ
E) 1504 kJ
Ans: C
Category: Difficult
Section: 6.6
76. Ozone (O3) in the atmosphere can be converted to oxygen gas by reaction with nitric
oxide (NO). Nitrogen dioxide is also produced in the reaction. What is the enthalpy
change when 8.50L of ozone at a pressure of 1.00 atm and 25°C reacts with 12.00 L of
nitric oxide at the same initial pressure and temperature? [H°f(NO) = 90.4 kJ/mol;
H°f(NO2) = 33.85 kJ/mol; H°f(O3) = 142.2 kJ/mol]
A) –69.2 kJ
B) –19.7 kJ
C) –1690 kJ
D) –97.6 kJ
E) –167 kJ
Ans: A
Category: Difficult
Section: 6.6
9.Identify the major ionic species present in an aqueous solution of K2SO4.
A) K2+, S6+, O48–
D) 2K+, S6+, 4O2–
2+
6+
2–
B) K , S , 4O
E) 2K+, SO42–
C) 2K+, S6+, O48–
Ans: E
Category: Easy
Section: 4.1
10. The distinguishing characteristic of all electrolyte solutions is that they
A) contain molecules.
D) always contain acids.
B) conduct electricity.
E) conduct heat.
C) react with other solutions.
Ans: B
Category: Easy
Section: 4.1
11. Based on the solubility rules, which one of the following compounds should be insoluble
in water?
A) NaCl
B) MgBr2
C) FeCl2
D) AgBr
E) ZnCl2
Ans: D
Category: Easy
Section: 4.2
12. Based on the solubility rules, which one of the following compounds should be insoluble
in water?
A) Na2SO4
B) BaSO4
C) CuSO4
D) MgSO4
E) Rb2SO4
Ans: B
Category: Easy
Section: 4.2
13. Based on the solubility rules, which one of the following compounds should be insoluble
in water?
A) CaCO3
B) (NH4)2CO3
C) Na2CO3
D) K2CO3
E) KNO3
Ans: A
Category: Easy
Section: 4.2
14. Based on the solubility rules, which one of the following should be soluble in water?
A) Hg2Cl2
B) Na2S
C) Ag2CO3
D) Ag2S
E) BaSO4
Ans: B
Category: Easy
Section: 4.2
Page 90
Chapter 4: Reactions in Aqueous Solution
15. Based on the solubility rules, which one of the following should be soluble in water?
A) AgBr
B) AgCl
C) Ag2CO3
D) AgNO3
E) Ag2S
Ans: D
Category: Easy
Section: 4.2
16. Based on the solubility rules, which one of the following should be soluble in water?
A) (NH4)3PO4
B) Ca3(PO4)2
C) AlPO4
D) Ag3PO4
E)
Mg3(PO4)2
Ans: A
Category: Easy
Section: 4.2
17. Based on the solubility rules, which one of the following should be soluble in water?
A) CaSO4
B) BaSO4
C) PbSO4
D) K2SO4
E) AgCl
Ans: D
Category: Easy
Section: 4.2
18. Based on the solubility rules, which of the following will occur when a solution
containing about 0.1 g of Pb(NO3)2(aq) is mixed with a solution containing 0.1 g of
KI(aq) /100 mL?
A) KNO3 will precipitate; Pb2+ and I– are spectator ions.
B) No precipitate will form.
C) Pb(NO3)2 will precipitate; K+ and I– are spectator ions.
D) PbI2 will precipitate; K+ and NO3– are spectator ions.
E) Pb2+ and I– are spectator ions, and PbI2 will precipitate.
Ans: D
Category: Medium
Section: 4.2
19. Based on the solubility rules, which of the following will occur if solutions of CuSO4(aq)
and BaCl2(aq) are mixed?
A) CuCl2 will precipitate; Ba2+ and SO42– are spectator ions.
B) CuSO4 will precipitate; Ba2+ and Cl– are spectator ions.
C) BaSO4 will precipitate; Cu2+ and Cl– are spectator ions.
D) BaCl2 will precipitate; Cu2+ and SO42– are spectator ions.
E) No precipitate will form.
Ans: C
Category: Medium
Section: 4.2
20. Based on the solubility rules, which of the following will occur when solutions of
ZnSO4(aq) and MgCl2(aq) are mixed?
A) ZnCl2 will precipitate; Mg2+ and SO42– will be spectator ions.
B) ZnSO4 will precipitate; Mg2+ and Cl– will be spectator ions.
C) MgSO4 will precipitate; Zn2+ and Cl– will be spectator ions.
D) MgCl2 will precipitate; Zn2+ and SO42– will be spectator ions.
E) No precipitate will form.
Ans: E
Category: Medium
Section: 4.2
Page 91
Chapter 4: Reactions in Aqueous Solution
21. Which of the following is the correct net ionic equation for the reaction that occurs when
solutions of Pb(NO3)2 and NH4Cl are mixed?
A) Pb(NO3)2(aq) + 2NH4Cl(aq)  NH4NO3(aq) + PbCl2(s)
B) Pb2+(aq) + 2Cl–(aq)  PbCl2(s)
C) Pb2+(aq) + 2NO3– (aq) + 2NH 4 (aq) + 2Cl–(aq)  2NH 4 (aq) + 2NO3– (aq) +
PbCl2(s)
D) NH4+(aq)+ NO3– (aq)  2NH4NO3(s)
E) No reaction occurs when the solutions are mixed.
Ans: B
Category: Medium
Section: 4.2
22. The common constituent in all acid solutions is
A) H2
B) H+
C) OH–
D) H2SO4
Ans: B
Category: Easy
Section: 4.3
E) Cl–
23. Which of the following compounds is a weak acid?
A) HF
B) HCl
C) HBr
D) HI
Ans: A
Category: Easy
Section: 4.1
E) HClO 4
24. Identify the major ions present in an aqueous LiOH solution.
A) Li2+, O–, H–
B) Li+, OH–
C) LiO–, H+
D)
+
, OH
Ans: B
Category: Easy
Section: 4.3
Li+, O2–, H+
25. Identify the major ions present in an aqueous HNO3 solution.
A) HN+, O2–
B) OH–, NO3–
C) OH–, NO
D) H+, N3–, O2–
+
–
H , NO3
Ans: E
Category: Easy
Section: 4.3
E)
Li–
E)
26. Identify the major ionic species present in an aqueous solution of H2SO4.
A) S6+, O36– (plus H2O as a neutral species)
B) H+, OH–, S6+, 3O2–
C) 2H+, S6+, 4O2–
D) H+, HSO4–
E) 2H+, SO42–
Ans: D
Category: Medium
Section: 4.3
27. What is the correct formula of the salt formed in the neutralization reaction of
hydrochloric acid with calcium hydroxide?
A) CaO
B) CaCl2
C) CaH2
D) CaCl
E) CaClH
Ans: B
Category: Medium
Section: 4.3
28. What is the chemical formula of the salt produced by the neutralization of hydrobromic
acid with magnesium hydroxide?
A) MgBr
B) Mg2Br3
C) Mg3Br2
D) Mg2Br
E) MgBr2
Ans: E
Category: Medium
Section: 4.3
Page 92
Chapter 4: Reactions in Aqueous Solution
29. What is the chemical formula of the salt produced by the neutralization of nitric acid with
calcium hydroxide?
A) CaNO3
B) Ca2(NO3)3
C) Ca3(NO3)2
D) Ca2NO3
E)
Ca(NO3)2
Ans: E
Category: Medium
Section: 4.3
30. What is the chemical formula of the salt produced by the complete neutralization of
sodium hydroxide with sulfuric acid?
A) Na2SO4
B) Na2(SO4)3
C) Na(SO4)2
D) NaSO3
E) Na3SO4
Ans: A
Category: Medium
Section: 4.3
31. What is the chemical formula of the salt produced by the neutralization of potassium
hydroxide with sulfuric acid?
A) KSO3
B) K2(SO4)3
C) K2SO4
D) K(SO4)2
E) KSO4
Ans: C
Category: Medium
Section: 4.3
32. The oxidation number of N in NaNO3 is
A) +6
B) +5
C) +3
D) –3
E) None of the above.
Ans: B
Category: Medium
Section: 4.4
33. The oxidation number of S in K2SO4 is
A) +6
B) +4
C) +2
D) –1
E) None of the above.
Ans: A
Category: Medium
Section: 4.4
34. The oxidation number of Mn in KMnO4 is
A) +8
B) +7
C) +5
D) –7
E)
Ans: B
Category: Medium
Section: 4.4
–8
35. The oxidation number of Fe in K3Fe(CN)6 is
A) +3
B) +2
C) +1
D) –3
E)
Ans: A
Category: Medium
Section: 4.4
–4
36. The oxidation number of Cr in Cr2O72– is
A) –12
B) –7
C) –2
D) +6
E) +7
Ans: D
Category: Medium
Section: 4.4
37. The oxidation number of Cl in ClO3– is
A) –1
B) +7
C) +5
D) +3
E) None of the above.
Ans: C
Category: Medium
Section: 4.4
38. The oxidation number of Cl in ClO4– is
A) –1
B) +1
C) +3
D) +5
E) None of the above.
Ans: E
Category: Medium
Section: 4.4
Page 93
Chapter 4: Reactions in Aqueous Solution
39. The highest possible oxidation number of nitrogen is
A) +8
B) +5
C) +3
D) +1
E)
Ans: B
Category: Medium
Section: 4.4
–3
40. For which one of the following acids is chlorine in the +5 oxidation state?
A) HCl
B) HClO
C) HClO2
D) HClO3
E) HClO4
Ans: D
Category: Medium
Section: 4.4
41. The highest possible oxidation number of carbon is
A) +8
B) +6
C) +4
D) +2
E)
Ans: C
Category: Medium
Section: 4.4
–4
42. Select the compound in which sulfur has its highest possible oxidation number.
A) H2S
B) SO2
C) SCl2
D) H2SO3
E) Na2SO4
Ans: E
Category: Medium
Section: 4.4
43. The oxidation number of N in N2H4 is
A) +4
B) –4
C) +2
D) –2
E) 0
Ans: D
Category: Medium
Section: 4.4
44. Which choice gives the correct oxidation numbers for all three elements in Rb2SO3 in the
order that the elements are shown in the formula?
A) –2, +6, –2
B) –1, +4, –3
C) +2, +4, –2
D) +1, +4, –2
E) +1,
+6, –6
Ans: D
Category: Medium
Section: 4.4
45. Which choice gives the correct oxidation numbers for all three elements in Ca(ClO)2 in
the order that the elements are shown in the formula?
A) +2, +1, –2
B) +2, –2, +1
C) +2, –3, +2
D) –2, +2, –1
E) –2,
+3, –2
Ans: A
Category: Medium
Section: 4.4
46. In the following redox reaction
4NH3 + 3Ca(ClO)2  2N2 + 6H2O + 3CaCl2
which element is oxidized and which is reduced?
A) H is oxidized and N is reduced
D) Cl is oxidized and O is reduced
B) N is oxidized and Cl is reduced
E) Cl is oxidized and N is reduced
C) N is oxidized and O is reduced
Ans: B
Category: Medium
Section: 4.4
Page 94
Chapter 4: Reactions in Aqueous Solution
47. Which one of the following is a redox reaction?
A) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
B) 2KBr(aq) + Pb(NO3)2(aq)  2KNO3(aq) + PbBr2(s)
C) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
D) H+(aq) + OH– (aq)  H2O(l)
E) CO32– (aq) + HSO4–(aq)  HCO3– (aq) + SO42– (aq)
Ans: A
Category: Medium
Section: 4.4
48. Which of the following equations does not represent an oxidation-reduction reaction?
A) 3Al + 6HCl  3H2 + AlCl3
B) 2H2O  2H2 + O2
C) 2NaCl + Pb(NO3)2  PbCl2 + 3NaNO3
D) 2NaI + Br2  2NaBr + I2
E) Cu(NO3)2 + Zn  Zn(NO3)2 + Cu
Ans: C
Category: Medium
Section: 4.4
49. In the following chemical reaction the oxidizing agent is
5H2O2 + 2MnO4– + 6H+  2Mn2+ + 8H2O + 5O2
A) H2O2
B) MnO4–
C) H+
D) Mn2+
Ans: B
Category: Difficult
Section: 4.4
E) O2
50. In the following chemical reaction the oxidizing agent is
5S + 6KNO3 + 2CaCO3  3K2SO4 + 2CaSO4 + CO2 + 3N2
A) S
B) N2
C) KNO3
D) CaSO4
E) CaCO3
Ans: C
Category: Difficult
Section: 4.4
51. Identify the oxidizing agent in the following chemical reaction.
2MnO4– + 5H2SO3  2Mn2+ + 5SO42– + 4H+ + 3H2O
A) MnO4–
B) H2SO3
C) Mn2+
D) SO42–
E) H+
Ans: A
Category: Difficult
Section: 4.4
52. Identify the reducing agent in the following chemical reaction.
5Fe2+(aq) + MnO4–(aq) + 8H+(aq)  5Fe3+(aq) + Mn2+(aq) + 4H2O(l)
A) Fe2+
B) MnO4–
C) H+
D) Mn2+
E) Fe3+
Ans: A
Category: Difficult
Section: 4.4
53. Identify the reducing agent in the following chemical reaction.
Cd + NiO2 + 2H2O  Cd(OH)2 + Ni(OH)2
A) Cd
B) NiO2
C) H2O
D) Cd(OH)2
E) Ni(OH)2
Ans: A
Category: Difficult
Section: 4.4
Page 95
Chapter 4: Reactions in Aqueous Solution
54. What element is oxidized in the following chemical reaction?
3Cu + 8HNO3  3Cu(NO3)2 + 2NO + 4H2O
A) Cu
B) H
C) N
D) O
E) H 2O
Ans: A
Category: Medium
Section: 4.4
55. What element is oxidized in the following chemical reaction?
NiO2 + Cd + 2H2O  Ni(OH)2 + Cd(OH)2
A) Ni
B) Cd
C) O
D) H
E) This is not a redox reaction.
Ans: B
Category: Medium
Section: 4.4
56. What element is oxidized in the following chemical reaction?
H2SO4 + Cd(OH)2  2H2O + CdSO4
A) H
B) S
C) O
D) Cd
E) this is not a redox reaction
Ans: E
Category: Medium
Section: 4.4
57. What element is reduced in the following chemical reaction?
Cu + 2H2SO4  CuSO4 + SO2 + 2H2O
A) Cu
B) H
C) S
D) O
E) H 2O
Ans: C
Category: Medium
Section: 4.4
58. Identify the elements that are oxidized and reduced in the following reaction.
KClO3(aq) + 6HBr(aq)  KCl(aq) + 3Br2(l) + 3H2O(l)
A) Br is oxidized and Cl is reduced
D) O is oxidized and Cl is reduced
B) Cl is oxidized and H is reduced
E) Cl is oxidized and Br is reduced
C) H is oxidized and O is reduced
Ans: A
Category: Medium
Section: 4.4
59. Predict the products of the following single replacement reaction.
Fe(s) + CuSO4(aq) 
A) Cu(s) + FeSO4(aq)
D) FeCuSO4(aq)
B) Fe(s) + Cu(s) + SO4(aq)
E) FeO(s) + CuSO3(aq)
C) CuS(s) + Fe2SO4(aq)
Ans: A
Category: Medium
Section: 4.4
60. Which of the following is an example of a disproportionation reaction?
A) 2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(l)
B) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
C) 2H2O2(aq)  2H2O(l) + O2(g)
D) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
E) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
Ans: C
Category: Medium
Section: 4.4
Page 96
Chapter 4: Reactions in Aqueous Solution
61. Which of the following represents a metal displacement reaction?
A) 2NaN3(s)  2Na(s) + 3N2(g)
B) Fe2O3(s) + 2Al(s)  2Fe(s) + Al2O3(s)
C) 3NO2(g) + H2O(l)  2HNO3(aq) + NO(g)
D) 2P(s) + 3Cl2(g)  2PCl3(g)
E) 2ZnS(s) + 3O2(g)  2ZnO(s) + 2SO2(g)
Ans: B
Category: Easy
Section: 4.4
62. Which of the following represents a halogen displacement reaction?
A) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
B) 2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)
C) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
D) 2KNO3(s)  2KNO2(s) + O2(g)
E) 2LiOH(aq) + H2SO4(aq)  Li2SO4(aq) + 2H2O(l)
Ans: A
Category: Easy
Section: 4.4
63. Which of the following represents a precipitation reaction?
A) 2H2(g) + O2(g)  2H2O(l)
B) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
C) 2KNO3(s)  2KNO2(s) + O2(g)
D) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
E) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
Ans: B
Category: Easy
Section: 4.2
64. Which of the following represents an acid-base neutralization reaction?
A) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
B) SO2(g) + H2O(l)  H2SO3(g)
C) LiOH(aq) + HNO3(aq)  LiNO3(aq) + H2O(l)
D) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
E) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
Ans: C
Category: Medium
Section: 4.4
65. Which of the following represents a hydrogen displacement reaction?
A) 2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(l)
B) 2KBr(aq) + Cl2(g)  2KCl(aq) + Br2(l)
C) N2(g) + 3H2(g)  2NH3(g)
D) CaBr2(aq) + H2SO4(aq)  CaSO4(s) + 2HBr(g)
E) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
Ans: E
Category: Medium
Section: 4.4
Page 97
Chapter 4: Reactions in Aqueous Solution
66. Which of the following represents a combustion reaction?
A) 2C2H6(g) + 7O2(g)  4CO2(g) + 6H2O(l)
B) LiOH(aq) + HNO3(aq)  LiNO3(aq) + H2O(l)
C) N2(g) + 3H2(g)  2NH3(g)
D) 2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)
E) 2Al(s) + 3H2SO4(aq)  Al2(SO4)3(aq) + 3H2(g)
Ans: A
Category: Easy
Section: 4.4
67. What mass of K2CO3 is needed to prepare 200. mL of a solution having a potassium ion
concentration of 0.150 M?
A) 4.15 g
B) 10.4 g
C) 13.8 g
D) 2.07 g
E) 1.49 g
Ans: D
Category: Medium
Section: 4.5
68. What mass of Na2SO4 is needed to prepare 350. mL of a solution having a sodium ion
concentration of 0.125 M?
A) 3.11 g
B) 24.9 g
C) 12.4 g
D) 6.21 g
E) 8.88 g
Ans: A
Category: Medium
Section: 4.5
69. What mass of Li3PO4 is needed to prepare 500. mL of a solution having a lithium ion
concentration of 0.175 M?
A) 6.75 g
B) 10.1 g
C) 19.3 g
D) 30.4 g
E) 3.38 g
Ans: E
Category: Medium
Section: 4.5
70. A 50.0 mL sample of 0.436 M NH4NO3 is diluted with water to a total volume of 250.0
mL. What is the ammonium nitrate concentration in the resulting solution?
A) 21.8 M
B) 0.459 M
C) 2.18  10–2 M
D) 8.72  10–2 M
E)
0.109 M
Ans: D
Category: Medium
Section: 4.5
71. A 20.00 mL sample of 0.1015 M nitric acid is introduced into a flask, and water is added
until the volume of the solution reaches 250. mL. What is the concentration of nitric
acid in the final solution?
A) 1.27 M
D) 3.25  10–2 M
B) 8.12  10–3 M
E) 5.08  10–4 M
C) 0.406 M
Ans: B
Category: Medium
Section: 4.5
72. A 3.682 g sample of KClO3 is dissolved in enough water to give 375. mL of solution.
What is the chlorate ion concentration in this solution?
A) 3.00  10–2 M
D) 1.65  10–2 M
–2
B) 4.41  10 M
E) 8.01  10–2 M
C) 0.118 M
Ans: E
Category: Medium
Section: 4.5
Page 98
Chapter 4: Reactions in Aqueous Solution
73. A 4.691 g sample of MgCl2 is dissolved in enough water to give 750. mL of solution.
What is the magnesium ion concentration in this solution?
A) 3.70  10–2 M
D) 4.93  10–2 M
B) 1.05  10–2 M
E) 0.131 M
–2
C) 6.57  10 M
Ans: C
Category: Medium
Section: 4.5
74. A 0.9182 g sample of CaBr2 is dissolved in enough water to give 500. mL of solution.
What is the calcium ion concentration in this solution?
A) 9.19  10–3 M
D) 4.59  10–3 M
B) 2.30  10–3 M
E) 1.25  10–3 M
–3
C) 2.72  10 M
Ans: A
Category: Medium
Section: 4.5
75. 35.0 mL of 0.255 M nitric acid is added to 45.0 mL of 0.328 M Mg(NO3)2. What is the
concentration of nitrate ion in the final solution?
A) 0.481 M
B) 0.296 M
C) 0.854 M
D) 1.10 M
E) 0.0295 M
Ans: A
Category: Difficult
Section: 4.5
76. 17.5 mL of a 0.1050 M Na2CO3 solution is added to 46.0 mL of 0.1250 M NaCl. What
is the concentration of sodium ion in the final solution?
A) 0.205 M
B) 0.119 M
C) 0.539 M
D) 0.148 M
E) 0.165 M
Ans: D
Category: Difficult
Section: 4.5
77. 25.0 mL of a 0.2450 M NH4Cl solution is added to 55.5 mL of 0.1655 M FeCl3. What
is the concentration of chloride ion in the final solution?
A) 0.607 M
B) 0.418 M
C) 1.35 M
D) 0.190 M
E) 0.276 M
Ans: B
Category: Difficult
Section: 4.5
78. When 38.0 mL of 0.1250 M H2SO4 is added to 100. mL of a solution of PbI2, a
precipitate of PbSO4 forms. The PbSO4 is then filtered from the solution, dried, and
weighed. If the recovered PbSO4 is found to have a mass of 0.0471 g, what was the
concentration of iodide ions in the original solution?
A) 3.10  10–4 M
D) 3.11  10–3 M
–4
B) 1.55  10 M
E) 1.55  10–3 M
C) 6.20  10–3 M
Ans: D
Category: Difficult
Section: 4.6
Page 99
Chapter 4: Reactions in Aqueous Solution
79. When 50.0 mL of a 0.3000 M AgNO3 solution is added to 50.0 mL of a solution of
MgCl2, an AgCl precipitate forms immediately. The precipitate is then filtered from the
solution, dried, and weighed. If the recovered AgCl is found to have a mass of 0.1183
g, what as the concentration of magnesium ions in the original MgCl2 solution?
A) 0.300 M
D) 2.06  10–5 M
B) 8.25  10–3 M
E) 4.13  10–3 M
–2
C) 1.65  10 M
Ans: B
Category: Difficult
Section: 4.6
80. When 20.0 mL of a 0.250 M (NH4)2S solution is added to 150.0 mL of a solution of
Cu(NO3)2, a CuS precipitate forms. The precipitate is then filtered from the solution,
dried, and weighed. If the recovered CuS is found to have a mass of 0.3491 g, what was
the concentration of copper ions in the original Cu(NO3)2 solution?
A) 3.65  10–3 M
D) 4.87  10–2 M
B) 1.22  10–2 M
E) 2.43  10–2 M
–2
C) 3.33  10 M
Ans: E
Category: Difficult
Section: 4.6
81. 34.62 mL of 0.1510 M NaOH was needed to neutralize 50.0 mL of an H2SO4 solution.
What is the concentration of the original sulfuric acid solution?
A) 0.0229 M
B) 0.218 M
C) 0.0523 M
D) 0.209 M
E) 0.105 M
Ans: C
Category: Medium
Section: 4.7
82. The concentration of oxalate ion (C2O42–) in a sample can be determined by titration with
a solution of permanganate ion (MnO4–) of known concentration. The net ionic
equation for this reaction is
2MnO4– + 5C2O42– + 16H+  2Mn2+ + 8H2O + 10CO2
A 30.00 mL sample of an oxalate solution is found to react completely with 21.93 mL of
a 0.1725 M solution of MnO4–. What is the oxalate ion concentration in the sample?
A) 0.02914 M
B) 0.4312 M
C) 0.1821 M
D) 0.3152 M
E)
0.05044 M
Ans: D
Category: Medium
Section: 4.8
83. One method of determining the concentration of hydrogen peroxide (H2O2) in a solution
is through titration with iodide ion. The net ionic equation for this reaction is
H2O2 + 2I– +2H+  I2 + 2H2O
A 50.00 mL sample of a hydrogen peroxide solution is found to react completely with
37.12 mL of a 0.1500 M KI solution. What is the concentration of hydrogen peroxide in
the sample?
A) 5.568  10–2 M
D) 0.4041 M
B) 0.2227 M
E) 0.1114 M
C) 0.1010 M
Ans: A
Category: Medium
Section: 4.8
Page 100
Chapter 4: Reactions in Aqueous Solution
84. Zinc dissolves in hydrochloric acid to yield hydrogen gas:
Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
What mass of hydrogen gas is produced when a 7.35 g chunk of zinc dissolves in 500.
mL of 1.200M HCl?
A) 0.605 g
B) 0.113 g
C) 0.302 g
D) 0.453 g
E) 0.227 g
Ans: E
Category: Medium
Section: 4.8
85. Zinc dissolves in hydrochloric acid to yield hydrogen gas:
Zn(s) + 2HCl(aq)  ZnCl2(aq) + H2(g)
When a 12.7 g chunk of zinc dissolves in 500. mL of 1.450M HCl, what is the
concentration of hydrogen ions remaining in the final solution?
A) 0.776 M
B) 0.388 M
C) 0.674 M
D) 1.06 M
E) 0 M
Ans: C
Category: Medium
Section: 4.8
86. Lithium metal dissolves in water to yield hydrogen gas and aqueous lithium hydroxide.
What is the final concentration of hydroxide ions when 5.500 g of lithium metal is
dropped into 750. mL of water?
A) 1.06 M
B) 0.528 M
C) 2.11 M
D) 0.792 M
E) 0.943 M
Ans: A
Category: Medium
Section: 4.8
87. When solid iron(II) hydroxide is added to water, the resulting solution contains 1.410–3g
of dissolved iron(II) hydroxide per liter of solution. What is the hydroxide ion
concentration in this solution?
A) 7.810–6 M
D) 3.110–5 M
B) 1.610–5 M
E) 4.010–3 M
C) 2.510–10 M
Ans: D
Category: Difficult
Section: 4.5
88. A 250. mL sample of 0.0328M HCl is partially neutralized by the addition of 100. mL of
0.0245M NaOH. Find the concentration of hydrochloric acid in the resulting solution.
A) 0.00700 M
B) 0.0164 M
C) 0.0383 M
D) 0.0230 M
E)
0.0575 M
Ans: B
Category: Difficult
Section: 4.7
89. A 350. mL sample of 0.276M HNO3 is partially neutralized by 125 mL of 0.0120M
Ca(OH)2. Find the concentration of nitric acid in the resulting solution.
A) 0.210 M
B) 0.00632 M
C) 0.203 M
D) 0.0240 M
E) 0.197
M
Ans: E
Category: Difficult
Section: 4.7
90. 158 mL of a 0.148M NaCl solution is added to 228 mL of a 0.369M NH4NO3 solution.
The concentration of ammonium ions in the resulting mixture is
A) 0.157 M
B) 0.218 M
C) 0.625 M
D) 0.369 M
E) 0 M
Ans: B
Category: Medium
Section: 4.5
Page 101
Chapter 4: Reactions in Aqueous Solution
91. 1.40 g of silver nitrate is dissolved in 125 mL of water. To this solution is added 5.00
mL of 1.50M hydrochloric acid, and a precipitate forms. Find the concentration of
silver ions remaining in solution.
A) 5.710–3 M
D) 0.121M
B) 6.3410–2 M
E) 5.910–3 M
C) 5.7710–2 M
Ans: A
Category: Difficult
Section: 4.6
92. Calcium sulfate dihydrate (commonly known as gypsum) dissolves in cold water to the
extent of 0.241 g per 100. cm3. What is the concentration of calcium ions in this
solution?
A) 1.7710–2 M
D) 3.5410–2 M
B) 2.8010–2 M
E) 1,4010–2 M
–3
C) 1.7710 M
Ans: E
Category: Difficult
Section: 4.5
93. Calcium nitrate tetrahydrate dissolves in cold water to the extent of 266 g per 100. cm3.
What is the concentration of nitrate ions in this solution?
A) 32.4M
B) 22.5M
C) 11.3M
D) 16.2M
E) 8.10M
Ans: B
Category: Difficult
Section: 4.5
94. Define solution, solute, and solvent.
Ans: A solution is a homogeneous mixture of two or more substances.
The substance present in a smaller amount is called the solute, while the substance
present in the larger amount is called the solvent.
Category: Easy
Section: 4.1
95. Identify the following compound as an electrolyte or nonelectrolyte: NaOH.
Ans: electrolyte
Category: Easy
Section: 4.1
96. Identify the following compound as an electrolyte or nonelectrolyte: H2SO4.
Ans: electrolyte
Category: Easy
Section: 4.1
97. Identify the following compound as an electrolyte or nonelectrolyte: Methanol (CH3OH).
Ans: nonelectrolyte
Category: Easy
Section: 4.1
98. Identify the following compound as an electrolyte or nonelectrolyte: C12H22O11(sucrose).
Ans: nonelectrolyte
Category: Easy
Section: 4.1
Page 102
Chapter 4: Reactions in Aqueous Solution
99. Identify the following compound as an electrolyte or nonelectrolyte: MgCl2.
Ans: electrolyte
Category: Easy
Section: 4.1
100. Identify the following compound as a strong electrolyte, weak electrolyte, or
nonelectrolyte: CH3OH (methanol).
Ans: nonelectrolyte
Category: Easy
Section: 4.1
101. Identify the following compound as a strong electrolyte, weak electrolyte, or
nonelectrolyte: CH3COOH.
Ans: weak electrolyte
Category: Easy
Section: 4.1
102. Identify the following compounds as a strong electrolytes, weak electrolytes, or
nonelectrolytes: KNO3, KNO2, HNO3, HNO2,
Ans: KNO3, KNO2, and HNO3 are strong electrolytes; HNO2 is a weak electrolyte.
Category: Medium
Section: 4.3
103. Identify the following compound as a strong electrolyte, weak electrolyte, or
nonelectrolyte: NH3.
Ans: weak electrolyte
Category: Medium
Section: 4.1
104. Identify the following compound as a strong electrolyte, weak electrolyte, or
nonelectrolyte: NH4Cl.
Ans: strong electrolyte
Category: Easy
Section: 4.1
105. Define and illustrate with an example the difference between an electrolyte and a
nonelectrolyte.
Ans: (Answers will vary.) An electrolyte is a substance that, when dissolved in water,
results in a solution that can conduct electricity. An example is sodium hydrogen
carbonate. A nonelectrolyte does not conduct electricity when dissolved in water.
An example would be sugar.
Category: Medium
Section: 4.1
106. Define precipitate and illustrate with an example.
Ans: (Answers will vary.) A precipitate is an insoluble solid that separates from a
solution.
CoCl2 (aq) + Na2CO3(aq)  CoCO3 (s) + 2NaCl (aq)
In this reaction, CoCO3 is a precipitate.
Category: Medium
Section: 4.2
Page 103
Chapter 4: Reactions in Aqueous Solution
107. Give an example of a monoprotic acid.
Ans: HNO3 (for example)
Category: Easy
Section: 4.3
108. Give an example of a diprotic acid.
Ans: H2CO3 (for example)
Category: Easy
Section: 4.3
109. Name and give the formulas for six strong acids.
Ans: hydrochloric acid, HCl; hydrobromic acid, HBr; hydroiodic acid, HI; nitric acid,
HNO3; sulfuric acid, H2SO4; perchloric acid, HClO4
Category: Easy
Section: 4.3
110. Give an example of a triprotic acid.
Ans: H3PO4
Category: Easy
Section: 4.3
111. Write the net ionic equation for the following reaction. Aqueous iron(III) sulfate is added
to aqueous sodium sulfide to produce solid iron(III) sulfide and aqueous sodium sulfate.
Ans: 2Fe3+(aq) + 3S2– (aq)  Fe2S3(s)
Category: Medium
Section: 4.2
112. Determine the oxidation number of each of the elements in Cs2Cr2O7?
Ans: the oxidation number of Cs is +1; the oxidation number of Cr is +6; the oxidation
number of O is –2
Category: Easy
Section: 4.4
113. Identify the element being oxidized in the following reaction.
4Al + 3O2  2Al2O3
Ans: Al
Category: Medium
Section: 4.4
114. Identify the element being reduced in the following reaction.
4Al + 3O2  2Al2O3
Ans: O
Category: Medium
Section: 4.4
115. Identify the oxidizing agent in the following reaction.
4Al + 3O2  2Al2O3
Ans: O2
Category: Medium
Section: 4.4
Page 104
Chapter 4: Reactions in Aqueous Solution
116. Identify the reducing agent in the following reaction.
4Al + 3O2  2Al2O3
Ans: Al
Category: Medium
Section: 4.4
117. Identify the element being oxidized in the following reaction.
2KBr + F2  Br2 + 2KF
Ans: Br
Category: Medium
Section: 4.4
118. Identify the element being reduced in the following reaction.
2KBr + F2  Br2 + 2KF
Ans: F
Category: Medium
Section: 4.4
119. Identify the oxidizing agent in the following reaction.
2KBr + F2  Br2 + 2KF
Ans: F2
Category: Medium
Section: 4.4
120. Identify the reducing agent in the following reaction.
2KBr + F2  Br2 + 2KF
Ans: Br– (or KBr)
Category: Medium
Section: 4.4
121. Determine the oxidation number of each of the elements BaNaPO4?
Ans: the oxidation number of Ba +2; the oxidation number of Na is +1; the oxidation
number of P is +5; the oxidation number of O is –2
Category: Easy
Section: 4.4
122. Determine the oxidation number of each of the elements in K2TaF7?
Ans: the oxidation number of K is +1; the oxidation number of Ta is +5; the oxidation
number of F is –1
Category: Easy
Section: 4.4
123. Thorium metal is prepared by reacting thorium oxide with calcium.
ThO2 + 2Ca  Th + 2CaO
Which substance is reduced in this process?
Ans: Th4+ is reduced
Category: Medium
Section: 4.4
Page 105
Chapter 4: Reactions in Aqueous Solution
124. Thorium metal is prepared by reacting thorium oxide with calcium.
ThO2 + 2Ca  Th + 2CaO
What is the reducing agent in this process?
Ans: Ca
Category: Medium
Section: 4.4
125. Thorium metal is prepared by reacting thorium oxide with calcium.
ThO2 + 2Ca  Th + 2CaO
Which substance is oxidized in this process?
Ans: Ca
Category: Medium
Section: 4.4
126. Thorium metal is prepared by reacting thorium oxide with calcium.
ThO2 + 2Ca  Th + 2CaO
What is the oxidizing agent in this process?
Ans: ThO4
Category: Medium
Section: 4.4
127. Batteries in our cars generate electricity by the following chemical reaction.
Pb + PbO2 + 2H2SO4  2PbSO4 + 2H2O
Which substance is reduced in this process?
Ans: Pb4+
Category: Medium
Section: 4.4
128. Batteries in our cars generate electricity by the following chemical reaction.
Pb + PbO2 + 2H2SO4  2PbSO4 + 2H2O
What is the reducing agent in this process?
Ans: Pb
Category: Medium
129. Batteries in our cars generate electricity by the following chemical reaction.
Pb + PbO2 + 2H2SO4  2PbSO4 + 2H2O
Which substance is oxidized in this process?
Ans: Pb
Category: Medium
Section: 4.4
130. Batteries in our cars generate electricity by the following chemical reaction.
Pb + PbO2 + 2H2SO4  2PbSO4 + 2H2O
What is the oxidizing agent in this process?
Ans: PbO2
Category: Medium
Section: 4.4
Page 106
Chapter 4: Reactions in Aqueous Solution
131. Describe the procedure used to make 3.0 liters of a 2.0 M KCl solution, starting with
solid KCl and water.
Ans: Determine the molar mass of KCl, which is 74.55 g/mol; weigh out 447.3 grams (6
mol) of KCl; dissolve the KCl in enough water to form exactly 3 liters of solution.
Category: Medium
Section: 4.5
132. What is the molarity of a solution that contains 5.0 moles of solute in 2.00 liters of
solution?
Ans: 2.5 M
Category: Easy
Section: 4.5
133. The solubility of Ba(NO3)2 is 130.5 grams per liter at 0°C. How many moles of
dissolved salt are present in 4.0 liters of a saturated solution of Ba(NO3)2 at 0ºC?
Ans: 2.0 moles
Category: Medium
Section: 4.5
134. What is the molar concentration of chloride ions in a solution prepared by mixing 100.
mL of 2.0 M KCl with 50. mL of a 1.5 M CaCl2 solution?
Ans: 2.3 M
Category: Difficult
135. What volume of concentrated nitric acid (15.0 M) is required to make 100. mL of a 3.0 M
nitric acid solution?
Ans: 20. mL
Category: Medium
Section: 4.5
136. During a titration the following data were collected. A 10. mL portion of an unknown
monoprotic acid solution was titrated with 1.0 M NaOH; 40. mL of the base were
required to neutralize the sample. What is the molarity of the acid solution?
Ans: 4.0 M
Category: Medium
Section: 4.7
137. During a titration the following data were collected. A 10. mL portion of an unknown
monoprotic acid solution was titrated with 1.0 M NaOH; 40. mL of the base were
required to neutralize the sample. How many moles of acid are present in 2.0 liters of
this unknown solution?
Ans: 8.0 moles
Category: Medium
Section: 4.7
138. If 145 grams of potassium nitrate were added to water to make 1,500 mL of solution,
what would be the molarity of the resulting solution?
Ans: 0.956 M
Category: Medium
Section: 4.5
Page 107
Chapter 4: Reactions in Aqueous Solution
139. During a titration the following data were collected. A 50.0 mL portion of an HCl
solution was titrated with 0.500 M NaOH; 200. mL of the base was required to neutralize
the sample. How many grams of HCl are present in 500. mL of this acid solution?
Ans: 36.5 g
Category: Medium
Section: 4.7
140. Identify the following as either a good or poor conductor of electricity: a crystal of
Na2SO4.
Ans: poor
Category: Easy
Section: 4.1
141. Identify the following as either a good or poor conductor of electricity: an aqueous
solution of Na2SO4.
Ans: good
Category: Easy
Section: 4.1
142. Identify the following as either a good or poor conductor of electricity: gasoline (C8H18).
Ans: poor
Category: Easy
Section: 4.1
143. Which substance is acting as a Brønsted acid in the following reaction?
HSO4– + NH4+  H2SO4 + NH3
Ans: NH4+
Category: Medium
Section: 4.3
144. Identify the Brønsted acid in the following reaction.
NH3 + H2O  NH4+ + OH–
Ans: H2O
Category: Medium
Section: 4.3
145. Write balanced molecular and net ionic equations for the reaction that would occur
between CaCl2(aq) and Na2CO3(aq). Be sure to include the correct states in your final
equations. If no reaction is expected, write “no reaction.”
Ans: Molecular equation: CaCl2(aq) + Na2CO3(aq)  CaCO3(s) + 2NaCl(aq)
Net ionic equation: Ca2+(aq) + CO32–(aq)  CaCO3(s)
Category: Medium
Section: 4.2
146. Write balanced molecular and net ionic equations for the acid-base neutralization reaction
between H3PO4(aq) and Ba(OH)2(aq). Be sure to include the correct states in your final
equations. If no reaction is expected, write “no reaction.”
Ans: Molecular equation: 2H3PO4(aq) + 3Ba(OH)2(aq)  Ba3(PO4)2(s) + 6H2O(l)
Net ionic equation: 2H3PO4(aq) + 3Ba2+(aq) + 6OH–(aq)  Ba3(PO4)2(s) + 6H2O(l)
Category: Difficult
Section: 4.3
Page 108
Chapter 4: Reactions in Aqueous Solution
147. Write balanced molecular and net ionic equations for the reaction that would occur
between Al(s) and Co(NO3)2(aq). Be sure to include the correct states in your final
equations. If no reaction is expected, write “no reaction.”
Ans: Molecular equation: 2Al(s) + 3Co(NO3)2(aq)  2Al(NO3)3(aq) + 3Co(s)
Net ionic equation: 2Al(s) + 3Co2+(aq)  2Al3+(aq) + 3Co(s)
Category: Medium
Section: 4.4
148. Write balanced molecular and net ionic equations for the reaction that would occur
between CuCl2(aq) and Pb(s). Be sure to include the correct states in your final equations.
If no reaction is expected, write “no reaction.”
Ans: Molecular equation: CuCl2(aq) + Pb(s)  Cu(s) + PbCl2(s)
Net ionic equation: Cu2+(aq) + 2Cl–(aq) + Pb(s)  Cu(s) + PbCl2(s)
Category: Difficult
Section: 4.4
149. A piece of copper metal was added to an aqueous solution of silver nitrate, and within a
few minutes it was observed that a grey crystalline solid formed on surface of the copper
and the solution turned a blue color characteristic of copper(II) ions.
Write the balanced chemical equation for this reaction.
Ans: Cu(s) + 2AgNO3(aq)  2Ag(s) + Cu(NO3)2(aq)
Category: Medium
Section: 4.4
150. A piece of copper metal was added to an aqueous solution of silver nitrate, and within a
few minutes it was observed that a grey crystalline solid formed on surface of the copper
and the solution turned a blue color characteristic of copper(II) ions.
Write the net ionic equation for this reaction.
Ans: Cu(s) + 2Ag+(aq)  Cu2+(aq) + 2Ag(s)
Category: Medium
Section: 4.4
151. A piece of lead metal was added to an aqueous solution of copper(II) nitrate, and within a
few minutes it was observed that the lead turned black and crumbled, and the blue
solution characteristic of copper(II) ions faded. (NOTE: Lead forms a 2+ ion when it
reacts.)
Write the balanced chemical equation for this reaction.
Ans: Pb(s) + Cu(NO3)2(aq)  Cu(s) + Pb(NO3)2(aq)
Category: Medium
Section: 4.4
152. A piece of lead metal was added to an aqueous solution of copper(II) nitrate, and within a
few minutes it was observed that the lead turned black and crumbled, and the blue
solution characteristic of copper(II) ions faded. (NOTE: Lead forms a 2+ ion when it
reacts.)
Write the net ionic equation for this reaction.
Ans: Pb(s) + Cu2+(aq)  Pb2+(aq) + Cu(s)
Category: Medium
Section: 4.4
Page 109
Chapter 4: Reactions in Aqueous Solution
153. A piece of zinc metal was added to an aqueous solution of lead(II) nitrate. After some
time it was observed that the zinc metal had appeared to fall apart and a solid had
accumulated at the bottom of the reaction vessel.
Write the balanced chemical equation for this reaction.
Ans: Zn(s) + Pb(NO3)2(aq)  Pb(s) + Zn(NO3)2(aq)
Category: Difficult
Section: 4.4
154. A piece of zinc metal was added to an aqueous solution of lead(II) nitrate. After some
time it was observed that the zinc metal had appeared to fall apart and a solid had
accumulated at the bottom of the reaction vessel.
Write the net ionic equation for this reaction.
Ans: Zn(s) + Pb2+(aq)  Zn2+(aq) + Pb(s)
Category: Difficult
Section: 4.4
155. The following experiments were carried out and observations recorded.
Expt. #1: copper metal was added to an aqueous solution of silver nitrate
Observation: The copper become coated with a substance.
Expt. #2: lead metal was added to an aqueous solution of copper(II) nitrate
Observation: The lead turned black and crumbled.
Expt. #3: zinc metal was added to an aqueous solution of lead(II) nitrate
Observation: The zinc appeared to fall apart.
Rank the metals from most active to least active.
Ans: most active Zn, next most active Pb, next most active Cu, least active Ag
Category: Difficult
Section: 4.4
156. Write a balanced molecular equation for the reaction that occurs when aqueous solutions
of potassium iodide and lead(II) nitrate are combined.
Ans: 2KI(aq) + Pb(NO3)2(aq)  PbI2(s) + 2KNO3(aq)
Category: Medium
Section: 4.2
157. If 73.5 mL of 0.200 M KI(aq) was required to precipitate all of the lead(II) ion from an
aqueous solution of lead(II) nitrate, how many moles of Pb2+ were originally in the
solution?
Ans: 7.35  10–3 moles of Pb2+
Category: Medium
Section: 4.6
158. Sugar dissolves in water, therefore it is a strong electrolyte.
Ans: False
Category: Medium
Section: 4.1
159. Silver chloride (AgCl) has an extremely low solubility in water; therefore, it is a weak
electrolyte.
Ans: False
Category: Medium
Section: 4.1
Page 110
Chapter 4: Reactions in Aqueous Solution
160. Most compounds containing chlorides, bromides, and iodides are soluble except those
containing Ag+, Hg22+, and Pb2+.
Ans: True
Category: Easy
Section: 4.2
161. The following reaction is an acid-base neutralization reaction.
H2SO4(aq) + CaBr2(aq)  CaSO4(s) + 2HBr(g)
Ans: False
Category: Easy
Section: 4.3
162. The oxidation number of N in NO is +7.
Ans: False
Category: Easy
Section: 4.4
163. Hydrogen is oxidized in the following chemical reaction.
H2 + Cl2  2HCl
Ans: True
Category: Medium
Section: 4.4
164. The following equation is an example of a net ionic equation.
Na+(aq) + Br–(aq) + Ag+(aq) + NO3–(aq)  AgBr(s) + Na+(aq) + NO3–(aq)
Ans: False
Category: Medium
Section: 4.2
165. The oxidation number of iodine increases by 6 in the following reaction.
2MnO4– + I– + H2O  2MnO2 + IO3– + 2OH–
Ans: True
Category: Medium
Section: 4.4
166. A weak acid or a weak base ionizes completely.
Ans: False
Category: Medium
Section: 4.3
167. The following reaction is a redox reaction.
CaC2(s) + H2O(l)  HCCH(g) + CaO(s)
Ans: False
Category: Medium
Section: 4.4
Definitions (only examples)
83. What is the definition of a “gas”?
Ans:
A “gas” is a substance in which the molecules are separated on the average by
distances that are large compared with the sizes of the molecules.
Category: Easy
Section: 5.1
84. What is standard temperature and standard pressure?
Ans:
0°C and 1 atm pressure
Category: Easy
Section: 5.2
Page 111
Chapter 4: Reactions in Aqueous Solution
Comprehensive questions/ Calculations(only show examples)
85.What is the pressure of the sample of gas trapped in the open-tube mercury manometer shown
below if atmospheric pressure is 742 mmHg and h = 16.7 cm?
Ans: 575 mmHg
Category: Easy
Section: 5.2
Page 112
Chapter 4: Reactions in Aqueous Solution
86. What is the pressure (in atmospheres) of the sample of gas trapped in the open-tube
mercury manometer shown below if atmospheric pressure is 735 mmHg and h = 8.3 cm?
Ans: 0.858 atm
Category: Easy
Section: 5.2
Page 113
Chapter 4: Reactions in Aqueous Solution
87. What is the pressure (in atmospheres) of the sample of gas trapped in the closed-tube
mercury manometer shown below if h = 23.6 cm?
Ans: 0.311 atm
Category: Easy
Section: 5.2
Page 114
Chapter 4: Reactions in Aqueous Solution
88. What is the pressure of the sample of gas trapped in the closed-tube mercury manometer
shown below if atmospheric pressure is 751 mmHg and h = 17.3 cm?
Ans: 173 mmHg (or 0.228 atm)
Category: Easy
Section: 5.2
89. What is the significance of the magnitude of the van der Waals “a” constant?
Ans: The magnitude of the van der Waals “a” constant reflects the strength of the
attractions between molecules of a given type of gas.
Category: Easy
Section: 5.8
90. How many grams of N2O, nitrous oxide, are contained in 500. mL of the gas at STP?
Ans: 0.982 g
Category: Easy
Section: 5.2
91. Calculate the density of N2O gas, in grams per liter, at 110°C and 12 atm.
Ans: 16.8 g/L
Category: Medium
Section: 5.4
92. Calculate the molar mass of a gaseous substance if 0.125 g of the gas occupies 93.3 mL
at STP.
Ans: 30.0 g/mol
Category: Medium
Section: 5.4
Page 115
Chapter 4: Reactions in Aqueous Solution
93. An aerosol can with a volume of 0.50 L has a bursting point of 2.6 atm.
contains 1.0 g CO2 and is heated to 400°C, will it burst?
Ans: No
Category: Medium
Section: 5.4
If the can
94. Phosgene, a chemical warfare agent used in World War I, consists of 12.41% C, 16.17%
O, and 71.69% Cl. 1.00 L of this gas at STP has a mass of 4.42 g. What is the
molecular formula of phosgene?
Ans: COCl2
Category: Medium
Section: 5.4
95. The van der Waals equation is a modification of the ideal gas equation. For what two
facts does this equation account?
Ans: (1) Real gas molecules exert forces on each other. (2) Gas molecules have volume.
Category: Easy
Section: 5.8
96. On a spring morning (20°C) you fill your tires to a pressure of 2.25 atmospheres. As you
ride along, the tire heats up to 45°C from the friction on the road. What is the pressure in
your tires now?
Ans: 2.44 atmospheres
Category: Medium
Section: 5.4
97. A gas-filled balloon with a volume of 12.5 L at 0.90 atm and 21°C is allowed to rise to
the stratosphere where the temperature is –5°C and the pressure is 1.0 millibar. What is
the final volume of the balloon? 1.000 atm = 1.013 bar.
Ans: 1.0  104 L
Category: Medium
Section: 5.4
98. What volume of H2 is formed at STP when 6.0 g of Al is treated with excess NaOH?
2NaOH + 2Al + 6H2O  2NaAl(OH)4 + 3H2(g)
Ans: 7.5 L
Category: Medium
Section: 5.5
99. A convenient way to produce very high purity oxygen in the laboratory is to decompose
KMnO4(s) at high temperature according to the following chemical equation:
2KMnO4(s)  K2MnO4(s) + MnO2(s) + O2(g)
If 2.50 L of O2(g) is needed at 1.00 atm and 20°C, what mass of KMnO4(s) should be
decomposed? Assume the decomposition of KMnO4(s) goes to completion.
Ans: 32.8 g
Category: Medium
Section: 5.5
Page 116
Chapter 4: Reactions in Aqueous Solution
100. What is V in the table below?
initial:
P
1,420 torr
V
75 mL
T
200. K
final:
760 torr
V
360. K
Ans: 250 mL
Category: Medium
Section: 5.4
101. What is P in the table below?
initial:
P
14 atm
V
1.0 L
final:
P
50. L
Ans: 0.28 L
Category: Medium
Section: 5.3
102. What is T in the table below?
initial:
V
91.8 mL
T
365 K
final:
45.8 mL
T
Ans: 182 K or –91.0°C
Category: Medium
Section: 5.3
103. What is P in the table below?
initial:
V
91.8 mL
P
1 atm
final:
45.8 mL
P
Ans: 2 atm
Category: Medium
Section: 5.3
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Chapter 4: Reactions in Aqueous Solution
104. Today is a beautiful day for a picnic in the mountains, so we seal our peanut butter
sandwich in a plastic sandwich bag at the base of the mountain. The approximate volume
of the sandwich bag not occupied by the sandwich is 200. mL. The pressure at the base of
the mountain is 1.0 atm. If the pressure at the top of the mountain is 0.80 atm, what is the
final volume of gas in our sandwich bag?
Ans: 250 mL
Category: Medium
Section: 5.3
105. Give five examples of elements that occur as gases at room temperature and pressure?
Ans: (Answers will vary.) Oxygen, nitrogen, helium, hydrogen, argon, chlorine
Category: Easy
Section: 5.1
106. Give five examples of compounds that exist as gases at room temperature and pressure.
Ans: (Answers will vary.) Ammonia, carbon dioxide, sulfur dioxide, nitrogen dioxide,
methane
Category: Easy
Section: 5.1
107. At constant pressure, the density of a gas depends on temperature. Does the density
increase or decrease as the temperature increases?
Ans: decrease
Category: Medium
Section: 5.3
108. In a weather forecast on a Seattle radio station the barometric pressure was reported to be
29.4 inches. What is this pressure in SI units? (1 inch = 25.4 mm, 1 atm = 760 mmHg)
Ans: 0.983 atm
Category: Easy
Section: 5.2
109. At STP, 1 mole of gas has a molar volume of 22.4 L. What is the density of oxygen at
STP?
Ans: 1.43 g/L
Category: Medium
Section: 5.4
110. Ammonium nitrite undergoes decomposition to produce only gases as shown below.
NH4NO2(s)  N2(g) + 2H2O(g)
How many liters of gas will be produced by the decomposition of 32.0 g of NH4NO2 at
525°C and 1.5 atm?
Ans: 65 L
Category: Medium
Section: 5.5
Page 118
Chapter 4: Reactions in Aqueous Solution
111. In an effort to address concerns about global warming, a power plant in Portland Oregon
is designed to take all of its exhaust gases from its boilers and recycle the CO2 using the
Solvay process to make sodium hydrogen carbonate. The reaction is shown below.
NH3(g) + H2O(l) + CO2(g) + NaCl(aq)  NaHCO3(aq) + NH4Cl(aq)
How many liters each of NH3 and CO2 (both at STP) would be consumed to produce 3.00
kg of sodium bicarbonate?
Ans: The volume of both NH3 and CO2 would be 800. liters.
Category: Medium
Section: 5.5
112. Baking powder is made up of sodium hydrogen carbonate and calcium hydrogen
phosphate. When baking powder is wet, these components react to produce carbon
dioxide. The equation for this reaction is given below.
NaHCO3(aq) + CaHPO4(aq)  NaCaPO4(aq) + CO2(g) + H2O(l)
Assuming all of the carbon dioxide was released as a gas, how many liters of CO2(g)
would be formed at room temperature from 4.00 g of NaHCO3 and excess CaHPO4?
Ans: Approximately 1.16 liters
Category: Medium
Section: 5.5
113. Packaged cake mixes usually contain baking powder, a mixture of sodium hydrogen
carbonate and calcium hydrogen phosphate that react to produce carbon dioxide gas when
they are heated in water. The CO2(g) formed allows the cake to “rise.” When such cake
mixes are used at high altitudes, often the cake will rise too much and collapse, unless
special instructions are followed. Why does this happen?
Ans: Due to the reduced atmospheric pressure, a greater volume of carbon dioxide is
created.
Category: Medium
Section: 5.4
114. Many automobiles produce about 5 grams of NO for each mile they are driven. How
many liters of NO gas at STP would be produced on a 100-mile trip?
Ans: 400 liters of NO
Category: Medium
Section: 5.5
115. A particular coal sample contains 2.32% S. When the coal is burned, the sulfur is
converted to sulfur dioxide gas. What volume of SO2(g), measured at 25°C and 749
mmHg, is produced by burning 2.0  106 lb of this coal? (1 lb = 454 g)
Ans: 1.6  107 liters
Category: Medium
Section: 5.5
116. At standard temperature and pressure, a given sample of water vapor occupies a volume
of 2.80 L. How many moles of water vapor are present?
Ans: 0.125 mol
Category: Easy
Section: 5.4
Page 119
Chapter 4: Reactions in Aqueous Solution
117. Gasoline (which can be considered to be octane, C8H18) burns in oxygen to produce
carbon dioxide and water. What volume of oxygen at STP is necessary to react with 1.0
gal of gasoline?
(The density of gasoline is 0.81 g/mL. 1 gal = 3.78 L)
Ans: 7,500 L
Category: Difficult
Section: 5.5
118. Gasoline (which can be considered to be octane, C8H18) burns in oxygen to produce
carbon dioxide and water. What volume of carbon dioxide at STP is generated as a
result of the combustion of 1.0 gal of gasoline?
(The density of gasoline is 0.81 g/mL. 1 gal = 3.78 L)
Ans: 4800 L
Category: Difficult
Section: 5.5
78. How many grams of ethylene (C2H4) would have to be burned to produce 450 kJ of heat?
C2H4(g) + 3O2
2(g) + H2
rxn = –1411 kJ/mol
Ans:
8.95 g
Category: Medium
Section: 6.4
79. Calculate the enthalpy of reaction for H2(g) + C2H4
2H6(g).
f(C2H4
f(C2H6(g)) = –84.7 kJ/mol]
Ans:
–137 kJ/mol
Category: Medium
Section: 6.6
80. The enthalpy of combustion of acetylene C2H2 is described by
C2H2(g) + (5/2)O2
2(g) + H2
rxn= –1299 kJ/mol
Calculate the enthalpy of formation of acetylene, given the following enthalpies of
formation
f[CO2(g)] = –393.5 kJ/mol
f[H2O(l)] = –285.8 kJ/mol
Ans:
226 kJ/mol
Category: Medium
Section: 6.6
81.
H2(g) +
H2O2
1
2
O2
2
2(g) + O2
f
= –285.8 kJ/mol
= 187.6 kJ/mol
rxn
for the reaction H2O2
Ans:
–98.2 kJ/mol
Category: Medium
Section: 6.6
rxn
2O(l)
+
1
2
O2(g),
82. The heat of solution of calcium chloride CaCl2 is –82.8 kJ/mol, and the combined heats
of hydration of 1 mole of gaseous calcium ions and 2 mole of gaseous chloride ions is –2327 kJ.
What is the lattice energy of calcium chloride?
Ans:
2,244 kJ/mol
Category: Medium
Section: 6.7
Page 120
Chapter 4: Reactions in Aqueous Solution
83. The heat of solution of NH4NO3 is 26.2 kJ/mol. Is heat evolved or absorbed when a
solution of NH4NO3 is diluted by addition of more water?
Ans:
Absorbed
Category: Easy
Section: 6.7
84. A 26.2 g piece of copper metal is heated from 21.5°C to 201.6°C. Calculate the
amount of heat absorbed by the metal. The specific heat of Cu is 0.385 J/g·°C.
Ans:
1,820 J
Category: Medium
Section: 6.5
85. A 0.1946 g piece of magnesium metal is burned in a constant-volume calorimeter that
has a heat capacity of 1349 J/°C. The calorimeter contains 500. g of water and the temperature
rise is 1.40°C. Calculate the heat of combustion of magnesium metal in kJ/g, given that the
specific heat of water = 4.184 J/g·°C.
Ans:
24.8 kJ/g
Category: Medium
Section: 6.5
86. A 0.3423 g sample of pentane, C5H12, was burned in a bomb calorimeter. The
temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22°C to
22.82°C. The heat capacity of the calorimeter is 2.21 kJ/°C. The heat capacity of water = 4.184
J/g·°C. How much heat was given off during combustion of the sample of pentane?
Ans:
16.6 kJ
Category: Medium
Section: 6.5
87. A 0.3423 g sample of pentane, C5H12, was burned in a bomb calorimeter. The
temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22°C to
22.82°C. The heat capacity of the calorimeter is 2.21 kJ/°C. The heat capacity of water = 4.184
J/g·°C. What is the heat of combustion, in kilojoules, per gram of pentane?
Ans:
48.6 kJ/g
Category: Medium
Section: 6.5
88. A 0.3423 g sample of pentane, C5H12, was burned in a bomb calorimeter. The
temperature of the calorimeter and the 1.000 kg of water contained therein rose from 20.22°C to
22.82°C. The heat capacity of the calorimeter is 2.21 kJ/°C. The heat capacity of water = 4.184
J/g·°C. What is the heat of combustion, in megajoules (MJ), per mole of pentane?
Ans:
3.50 MJ/mol
Category: Medium
Section: 6.5
89. The heat of combustion of propane, C3H8, 2220 kJ/mol. The specific heat of copper is
block of copper from 25.0°C to 65.0°C, assuming none of the heat is lost to the surroundings
Ans:
3.06 g
Category: Medium
Section: 6.5
90. The residential rate for natural gas is about $15 per thousand cubic foot. Burning one
cubic foot of natural gas releases about 1080 kJ of heat. How much would it cost to heat the
Page 121
Chapter 4: Reactions in Aqueous Solution
water in a 25,000 gallon swimming pool from 52°F to 78°F, assuming all of the heat from
burning the natural gas went towards warming the water? (1 gal = 3.785 L; the specific heat of
water = 4.184 J/g·°C)
Ans:
$79
Category: Difficult
Section: 6.5
91.
rxn = –56.2 kJ/mol. How much heat
is released when 125 mL of 1.750 M HCl is mixed with 195 mL of 0.667 M NaOH?
Ans:
7.31 kJ
Category: Difficult
Section: 6.5
92. The heat released when one mole of water is formed from the elements is 1,198 kJ. An
experiment was conducted that permitted water to form in this manner, and the heat was
contained in 2.0 liters of water. The water temperature before the reaction was 34.5°C, and after
the reaction it had risen to 52.0°C. How many moles of water were formed? (The specific
heat of water is 4.184 J/g·°C.)
Ans:
0.12 mole
Category: Medium
Section: 6.5
93. When an automobile engine starts, the metal parts immediately begin to absorb heat
released during the combustion of gasoline. How much heat will be absorbed by a 165 kg iron
engine block as the temperature rises from 15.7°C to 95.7°C? (The specific heat of iron is 0.489
J/g·°C.)
Ans:
6,450 kJ
Category: Medium
Section: 6.5
94.
rxn for the following reaction is –6535 kJ/mol.
2C6H6(l) + 15O2
2(g) + 6H2O(g)
How many kilojoules of heat will be evolved during the combustion of 16.0 g of
C6H6(l)?
Ans:
669 kJ
Category: Medium
Section: 6.4
95. What would be the standard enthalpy change for the reaction of one mole of H2(g) with
one mole of Cl2(g) to produce two moles of HCl(g) at standard state conditions?
f (HCl(g))= –92.3 kJ/mol]
Ans:
–185 kJ
Category: Medium
Section: 6.6
96. What is the standard enthalpy of formation of H2(g) at 25°C?
Ans:
0 kJ/mol
Category: Easy
Section: 6.6
97.
rxn for the reaction
CH4(g) + 2O2
2(g) + 2H2O(l).
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Chapter 4: Reactions in Aqueous Solution
(CH4(g)) = –
f
285.5 kJ/mol]
Ans:
-889.7 kJ/mol
Category: Medium
Section: 6.6
f
98.
(CO2(g)) = –
for the reaction
2Ag2S(s) + 2H2
2S(g) + O2(g).
(Ag
S(s))
=
–
f
2
f (H2S(g)) = –
285.5 kJ/mol]
Ans:
595.2 kJ/mol
Category: Medium
Section: 6.6
f
(H2O(l)) = –
rxn
f
(H2O(l)) = –
99.
rxn for the reaction
2Na(s) + 2H2
2(g).
f (NaOH(aq)) = –
f (H2O(l)) = –285.5 kJ/mol]
Ans:
–282.6 kJ
Category: Medium
Section: 6.6
100.
The specific heat of silver is 0.235 J/g·°C. How many joules of heat are required
to heat a 75 g silver spoon from 20°C to 35°C?
Ans:
260 J
Category: Easy
Section: 6.5
101.
At body temperature 2,404 joules of energy are required to evaporate 1.00 g of
water. After vigorous exercise, a person feels chilly because the body is giving up heat to
evaporate the perspiration. A typical person perspires 25 mL of water after 20. minutes of
exercise. How much body heat is this person using to evaporate this water?
4
Ans:
J
Category: Easy
Section: 6.4
102.
The combustion of one mole of benzene, C6H6, in oxygen liberates 3268 kJ of heat.
The products of the reaction are carbon dioxide and water. How much heat is given off when
183 g of oxygen are reacted with excess benzene?
Ans:
2490 kJ
Category: Difficult
Section: 6.4
103.
A feverish student weighing 75 kilograms was immersed in 400. kg of water at
4.0°C to try to reduce the fever. The student's body temperature dropped from 40.0°C to 37.0°C.
Assuming the specific heat of the student to be 3.77 J/g·°C, what was the final temperature of the
water?
Ans:
4.5°C
Category: Difficult
Section: 6.5
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