60) Given the data in the table below and ΔH°rxn for the reaction
SO2Cl2 (g) + 2H2O (l) → H2SO4 (l) + 2HCl (g) ΔH° = -62 kJ
ΔH°f of HCl (g) is ________ kJ/mol.
A) -184
B) 60
C) –92
D) 30
E) Insufficient data are given.
61) A 25.5-g piece of cheddar cheese contains 37% fat, 28% protein, and 4% carbohydrate. The respective
fuel values for protein, fat, and carbohydrate are 17, 38, and 17 kJ/g, respectively. The fuel value for this
piece of cheese is ________ kJ.
A) 450
B) 330
C) 790
D) 99
E) 260
62) The average fuel value of sugars is 17 kJ/g. A 2.0 L pitcher of sweetened Kool-Aid® contains 400 g of
sugar. What is the fuel value (in kJ) of a 500 mL serving of Kool-Aid®? (Assume that the sugar is the only
fuel source.)
A) 4.2 × 104 kJ
B) 1.7 × 103 kJ
C) 1.7 × 106 kJ
D) 1.7 × 102 kJ
E) 17 kJ
63) A meal containing a burger, fries, and a milkshake contains 53.0 grams of fat, 38.0 grams of protein,
and 152 grams of carbohydrate. The respective fuel values for protein, fat, and carbohydrate are 17, 38,
and 17 kJ/g, respectively. If swimming typically burns 1100.0 kJ/hour, ________ minutes of swimming are
required to completely burn off the meal.
A) 4.78
B) 33.5
C) 62.5
D) 10.5
E) 286
64) A slice of apple pie contains 14.0 grams of fat, 2.00 grams of protein, and 52.0 grams of carbohydrate.
The respective fuel values for protein, fat, and carbohydrate are 17, 38, and 17 kJ/g, respectively. If cycling
typically burns 1000.0 kJ/hour, ________ minutes of cycling are required to completely burn off the slice
of pie.
A) 1.45
B) 4.66
C) 8.25
D) 87.0
E) < 1
5.3 Algorithmic Questions
1) The kinetic energy of a 26.9-g object moving at a speed of 81.9 m/s is ________ J.
A) 145
B) 0.950
C) 90.2
D) 90200
E) 1450
2) The kinetic energy of a 23.2-g object moving at a speed of 98.7 m/s is ________ J.
A) 145
B) 113
C) 1450
D) 0.950
E) 113000
3) At what velocity (m/s) must a 19.9 g object be moving in order to possess a kinetic energy of 1.0 J?
A) 0.35 m/s
B) 2.8 m/s
C) 0.13 m/s
D) 0.031 m/s
E) 0.016 m/s
4) At what velocity (m/s) must a 417.3 g object be moving in order to possess a kinetic energy of 3.2 J?
A) 0.12 m/s
B) 26 m/s
C) 0.015 m/s
D) 0.0038 m/s
E) 0.00024 m/s
5) When work is done on a system, w will be a ________ value.
A) positive
B) negative
C) very large
D) very small
E) There is not enough information given to determine the answer.
6) The value of ΔE for a system that performs 139 kJ of work on its surroundings and gains 54kJ of heat is
________ kJ.
A) –85
B) 193
C) 7506
D) 85
E) –193
7) The value of ΔE for a system that performs 19 kJ of work on its surroundings and loses 9kJ of heat is
________ kJ.
A) –28
B) 28
C) 171
D) 10
E) –10
8) Calculate the work (kJ) done during a reaction in which the internal volume expands from 19 L to 48 L
against an outside pressure of 2.5 atm.
A) -7.3 kJ
B) 17 kJ
C) 7.3 kJ
D) -17 kJ
E) 0 kJ; No work is done.
9) Calculate the work (kJ) done during a reaction in which the internal volume expands from 14 L to 50 L
against a vacuum (an outside pressure of 0 atm).
A) 0; kJ No work is done.
B) 3.6 kJ
C) -3.6 kJ
D) 6.5 kJ
E) -6.5 kJ
10) Calculate the work (kJ) done during a reaction in which the internal volume contracts from 83 L to
13 L against an outside pressure of 4.4 atm.
A) 31 kJ
B) 43 kJ
C) -31 kJ
D) -43 kJ
E) 0 kJ; No work is done.
11) The value of ΔE for a system that performs 151 kJ of work on its surroundings and loses 79 kJ of heat
is ________ kJ.
A) +230.
B) -230.
C) +72
D) –72
E) -151
12) Calculate the value of ΔE in joules for a system that loses 115 J of heat and has 150 J of work
performed on it by the surroundings.
A) -115 J
B) -35 J
C) +35 J
D) +265 J
E) -265 J
13) The value of ΔH° for the reaction below is –72 kJ. ________ kJ of heat are released when 5.5 mol of
HBr is formed in this reaction.
H2 (g) + Br2 (g) → 2HBr (g)
A) 144
B) 72
C) 0.44
D) 198
E) –72
14) The value of ΔH° for the reaction below is –126 kJ. The amount of heat that is released by the reaction
of 10.0 g of Na2O2 with water is ________ kJ.
2Na2O2 (s) + 2H2O (l) → 4NaOH (s) + O2 (g)
A) 8.08
B) 16.2
C) 67.5
D) 32.3
E) -126
15) The value of ΔH° for the reaction below is –482 kJ. Calculate the heat (kJ) released to the surroundings
when 10.0 g of CO (g) reacts completely.
2CO (g) + O2 (g) → 2CO2 (g)
A) 2410 kJ
B) 172 kJ
C) 86.0 kJ
D) 482 kJ
E) -482 kJ
16) In the presence of excess oxygen, methane gas burns in a constant-pressure system to yield carbon
dioxide and water:
CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) △H = -890.0 kJ
Calculate the value of q (kJ) in this exothermic reaction when 1.80 g of methane is combusted at constant
pressure.
A) -100.1 kJ
B) 0.0324 kJ
C) -0.0100 kJ
D) 30.9 kJ
E) -1.00 × 105 kJ
17) Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction:
2H2O2 (l) → 2H2O (l) + O2 (g) △H = -196 kJ
Calculate the value of q (kJ) in this exothermic reaction when 1.50 g of hydrogen peroxide decomposes at
constant pressure?
A) -8.65 kJ
B) -4.32 kJ
C) -0.0578 kJ
D) 3.84 kJ
E) -8.65 × 103 kJ
18) The combustion of titanium with oxygen produces titanium dioxide:
Ti (s) + O2 (g) → TiO2 (s)
When 0.610 g of titanium is combusted in a bomb calorimeter, the temperature of the calorimeter
increases from 25.00 °C to 50.50 °C. In a separate experiment, the heat capacity of the calorimeter is
measured to be 9.84 kJ/K. The heat of reaction for the combustion of a mole of Ti in this calorimeter is
________ kJ/mol.
A) 2.09
B) 4.14
C) -311
D) -0.154
E) -1.98 × 104
19) A sample of aluminum metal absorbs 11.2 J of heat, upon which the temperature of the sample
increases from 23.2 °C to 30.5 °C. Since the specific heat capacity of aluminum is 0.90 J/g–K, the mass of
the sample is ________ g.
A) 72
B) 1.7
C) 10.
D) 65
E) 7.3
20) A sample of calcium carbonate [CaCO3 (s)] absorbs 40.3 J of heat, upon which the temperature of the
sample increases from 20.8 °C to 27.3 °C. If the specific heat of calcium carbonate is 0.82 J/g-K, what is the
mass (in grams) of the sample?
A) 7.6 g
B) 5.1 g
C) -7.6 g
D) 0.13 g
E) 5.3 g
21) The temperature of a 11.8 g sample of calcium carbonate [CaCO3 (s)] increases from 24.8 °C to 38.0 °C.
If the specific heat of calcium carbonate is 0.82 J/g-K, how many joules of heat are absorbed?
A) 130 J
B) 0.92 J
C) -130 J
D) -0.92 J
E) 11 J
22) An 6.11 g sample of calcium carbonate [CaCO3 (s)] absorbs 84 J of heat, upon which the temperature
of the sample increases from 19.2 °C to 35.9 °C. What is the specific heat of calcium carbonate?
A) 0.82 J/g-K
B) -0.82 J/g-K
C) 31 J/g-K
D) 230 J/g-K
E) 8600 J/g-K
23) A sample of iron absorbs 81.0 J of heat, upon which the temperature of the sample increases from 19.7
°C to 28.2 °C. If the specific heat of iron is 0.450 J/g-K, what is the mass (in grams) of the sample?
A) 21.2 g
B) 4.29 g
C) -21.2 g
D) 0.0472 g
E) 3.83 g
24) The temperature of a 35.1 g sample of iron increases from 24.5 °C to 31.8 °C. If the specific heat of iron
is 0.450 J/g-K, how many joules of heat are absorbed?
A) 115 J
B) 0.0936 J
C) -115 J
D) 0.722 J
E) 3.29 J
25) A 22.9 g sample of iron absorbs 155 J of heat, upon which the temperature of the sample increases
from 23.9 °C to 38.9 °C. What is the specific heat of iron?
A) 0.451 J/g-K
B) -0.451 J/g-K
C) 237 J/g-K
D) 102 J/g-K
E) 53,200 J/g-K
26) The specific heat capacity of liquid water is 4.18 J/g-K. How many joules of heat are needed to raise
the temperature of 7.25 g of water from 20.0 °C to 44.1 °C?
A) 41.8 J
B) 730 J
C) 1.94 × 103 J
D) 2.39 × 10-2 J
E) 66.8 J
27) The specific heat capacity of methane gas is 2.20 J/g–K. How many joules of heat are needed to raise
the temperature of 7.25 g of methane from 22.0 °C to 57.0 °C?
A) 115 J
B) 558 J
C) 1.26 × 103 J
D) 8.67 × 10-3 J
E) 41.3 J
28) The specific heat capacity of liquid mercury is 0.14 J/g-K. How many joules of heat are needed to raise
the temperature of 6.00 g of mercury from 25.1 °C to 65.3 °C?
A) 1.7 × 103 J
B) 34 J
C) 76 J
D) 5.8 × 10-4 J
E) 2.2 J
29) The specific heat capacity of solid copper metal is 0.385 J/g-K. How many joules of heat are needed to
raise the temperature of a 2.12-kg block of copper from 25.0 °C to 99.9 °C?
A) 4.12 × 105 J
B) 61.1 J
C) 6.11 × 104 J
D) 2.42 × 10-6 J
E) 0.00242 J
30) A 4.50-g sample of liquid water at 25.0 °C is heated by the addition of 133 J of energy. The final
temperature of the water is ________ °C. The specific heat capacity of liquid water is 4.18 J/g–K.
A) 149
B) 25.1
C) -17.9
D) 32.1
E) 7.07
31) The ΔH for the solution process when solid sodium hydroxide dissolves in water is 44.4 kJ/mol. When
a 12.6-g sample of NaOH dissolves in 250.0 g of water in a coffee–cup calorimeter, the temperature
increases from 23.0 °C to ________°C. Assume that the solution has the same specific heat as liquid water,
i.e., 4.18 J/g–K.
A) 35.2
B) 24.0
C) 36.4
D) 35.7
E) 40.2
32) A 50.0-g sample of liquid water at 25.0 °C is mixed with 23.0 g of water at 79.0 °C. The final
temperature of the water is ________ °C.
A) 123
B) 27.3
C) 52.0
D) 231
E) 42.0
33) A 5.00-g sample of copper metal at 25.0 °C is heated by the addition of 133 J of energy. The final
temperature of the copper is ________°C. The specific heat capacity of copper is 0.38 J/g-K.
A) 35.1
B) 25.0
C) 45.0
D) 95.0
E) 70.0
34) The temperature of a 24.3 g sample of gold increases from 23.7 °C to 31.5 °C. If the specific heat of
gold is 0.129 J/g-K, how many joules of heat are absorbed?
A) 24.5 J
B) 0.0414 J
C) -24.5 J
D) 0.293 J
E) 1.01 J
35) What is the enthalpy change (in kJ) of a chemical reaction that raises the temperature of 250.0 mL of
solution having a density of 1.25 g/mL by 3.33 °C? (The specific heat of the solution is 3.74 J/g–K.)
A) -7.43 kJ
B) -12.51 kJ
C) 8.20 kJ
D) -3.89 kJ
E) 6.51 kJ
36) A 5-ounce cup of raspberry yogurt contains 6.0 g of protein, 2.0 g of fat, and 16.3 g of carbohydrate.
The fuel values for protein, fat, and carbohydrate are 17, 38, and 17 kJ/g, respectively. The fuel value of
this cup of yogurt is ________ kJ.
A) 460
B) 520
C) 280
D) 720
E) 72
5.4 Short Answer Questions
1) ________ is defined as the energy used to move an object against a force.
2) Given the equation
H2O (l) → H2O (g) ΔHrxn = 40.7 kJ at 100 °C
Calculate the mass of liquid water (in grams) at 100 °C that can converted to vapor by absorbing 2400 J of
heat.
3) Given the equation
H2O (l) → H2O (g) ΔHrxn = 40.7 kJ at 100 °C
Calculate the heat required to convert 3.00 grams of liquid water at 100 °C to vapor.
4) When 0.800 grams of NaOH is dissolved in 100.0 grams of water, the temperature of the solution
increases from 25.00 °C to 27.06 °C. The amount of heat absorbed by the water is ________ J. (The specific
heat of water is 4.18 J/g-°C.)
5) Given the equation:
CH4 (g) + 2 O2 (g) → CO2 (g) + H2O (l) ΔH = -890.0 kJ
The heat liberated when 34.78 grams of methane (CH4) are burned in an excess amount of oxygen is
________ kJ.
6) The standard enthalpy change of a reaction is the enthalpy change when all reactants and products are
at ________ pressure and a specific temperature.
7) Coal contains hydrocarbons of high molecular weight as well as compounds containing ________,
oxygen, or nitrogen.
5.5 True/False Questions
1) Work equals force times distance.
2) One joule equals 1 kg-m2/s2.
3) Units of energy include newtons, joules, and calories.
4) The primary component of natural gas is propane.
5) Renewable energy sources are essentially inexhaustible.
6) Petroleum is a liquid composed of hundreds of compounds.