CHAPTER
3
SOLUTIONS MANUAL
Matter—Properties and Changes
Section 3.1 Properties of Matter
b. Iron is more dense than aluminum.
pages 70–75
physical
Problem-Solving Lab
c. Magnesium burns brightly when ignited.
1. Explain why the flow of a compressed gas must
be controlled for practical and safe use.
The flow of compressed gas must be controlled
to control the amount and the rate at which gas
is released.
chemical
d. Oil and water do not mix.
physical
e. Mercury melts at ⫺39°C.
2. Predict what would happen if the valve on a full
tank of compressed gas were suddenly opened
all the way or if the tank were accidentally
punctured.
Without the regulator device, the gas would rush
out of the tank with a force powerful enough to
transform the tank into a dangerous, uncontrolled
projectile.
Section 3.1 Assessment
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
page 75
physical
4. Organize Create a chart that compares
physical and chemical properties. Give two
examples for each type of property.
The chart should make clear that physical
properties can be observed without changing
the composition of the sample, which is not the
case for chemical properties. Mass and density
are examples of physical properties. Fermentation
and rusting are examples of chemical properties.
1. Create a table that describes the three common
states of matter in terms of their shape, volume,
and compressibility.
Volume
Shape
Compressibility
Solid
Definite
Definite
Incompressible
Liquid
Definite
Takes shape of
container and
fills container
to the extent of
its own volume
Virtually
incompressible
Takes shape of
container
Compressible
Gas
Fills
volume of
container
Section 3.2 Changes in Matter
pages 76–79
Practice Problems
page 78
5. Use the data in the table to answer the
following questions.
Aluminum and Liquid Bromine Reaction
2. Describe the characteristics that identify a
Aluminum
Liquid bromine
Compound
Before Reaction
After Reaction
10.3 g
0.0 g
100.0 g
8.5 g
0.0 g
sample of matter as being a substance.
The sample of matter must have a uniform and
unchanging composition to be a substance.
3. Classify each of the following as a physical or
chemical property.
a. Iron and oxygen form rust.
How many grams of bromine reacted? How
many grams of compound were formed?
amount of bromine that reacted 100.0 g 8.5 g 91.5 g
amount of compound formed 100.0 g 10.3 g 8.5 g 101.8 g
chemical
Solutions Manual
Chemistry: Matter and Change • Chapter 3
35
3
SOLUTIONS MANUAL
6. From a laboratory process designed to sepa-
rate water into hydrogen and oxygen gas, a
student collected 10.0 g of hydrogen and 79.4 g
of oxygen. How much water was originally
involved in the process?
massreactants massproducts
massproducts masshydrogen massoxygen
masswater electrolyzed masshydrogen massoxygen
masswater electrolyzed 10.0 g 79.4 g 89.4 g
7. A student carefully placed 15.6 g of sodium in
a reactor supplied with an excess quantity of
chlorine gas. When the reaction was complete,
the student obtained 39.7 g of sodium chloride.
Calculate how many grams of chlorine gas
reacted. How many grams of sodium reacted?
Section 3.2 Assessment
page 79
10. Classify each example as a physical change or
a chemical change.
a. crushing an aluminum can
physical
b. recycling used aluminum cans to make new
physical
chloride
masssodium 15.6 g
chloride
Yes. Mass of reactants equals mass of products.
aluminum cans
massreactants massproducts
masssodium
unknown amount of NH3(g) to produce 157.5 g
of NH4Cl(s). How many grams of NH3(g)
reacted? Is the law of conservation of mass
observed in the above reaction? Justify your
answer.
157.5 g 106.5 g 51 g
massreactants masswater electrolyzed
masssodium masschlorine masssodium
9. Challenge 106.5 g of HCl(g) react with an
39.7 g
Substituting and solving for masschlorine yields
15.6 g masschlorine 39.7 g
masschlorine 39.7 g 15.6 g 24.1 g used in the
reaction.
Because the sodium reacts with excess chlorine,
all of the sodium (15.6 g) is used in the reaction.
c. aluminum combining with oxygen to form
aluminum oxide
chemical
11. Describe the results of a physical change and
list three examples of physical change.
During a physical change, a substance is altered
but its composition does not change. Examples
will vary but may include changes such as
melting, freezing, boiling, bending, and tearing.
8. A 10.0-g sample of magnesium reacts with
oxygen to form 16.6 g of magnesium oxide.
How many grams of oxygen reacted?
massreactants massproducts
massmagnesium massoxygen massmagnesium oxide
massmagnesium 10.0 g
massmagnesium oxide 16.6 g
12. Describe the results of a chemical change. List
four indicators of chemical change.
During a chemical change, the composition of
a substance is altered. Possible indicators of
chemical change include a change in color, odor,
temperature, and the formation of a gas or solid
from a liquid.
10.0 g massoxygen 16.6 g
massoxygen 16.6 g 10.0 g 6.6 g
36
Chemistry: Matter and Change • Chapter 3
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CHAPTER
CHAPTER
3
13. Calculate Solve each of the following.
a. In the complete reaction of 22.99 g of
sodium with 35.45 g of chlorine, what mass
of sodium chloride is formed?
masssodium chloride masssodium masschloride
masssodium chloride 22.99 g 35.45 g 58.44 g
b. A 12.2-g sample of X reacts with a sample
of Y to form 78.9 g of XY. What is the mass
of Y that reacted?
massX massY massXY
massY massXY massX 78.9 g 12.2 g 66.7 g
14. Evaluate A friend tells you, “Because
composition does not change during a physical
change, the appearance of a substance does not
change.” Is your friend correct? Explain.
SOLUTIONS MANUAL
17. Describe the separation technique that could be
used to separate each of the following mixtures.
a. two colorless liquids
distillation
b. a nondissolving solid mixed with a liquid
filtration
c. red and blue marbles of same size and mass
manually separating the marbles by color
18. Concept Map Sketch a rough chart that
summarizes the relationship between matter,
elements, mixtures, compounds, pure
substances, homogeneous mixtures, and
heterogeneous mixtures.
Chart will be similar to Figure 3.19.
Matter
The statement is incorrect. While the composition
does not change, a change in appearance often
accompanies a physical change.
Mixtures
Physical
changes
Pure substances
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Section 3.3 Mixtures of Matter
pages 80–83
Section 3.3 Assessment
page 83
Chemical
changes
Heterogeneous
mixtures
Homogeneous
mixtures
Elements
Compounds
dirt, blood,
milk
lemonade, gasoline,
steel
oxygen, gold,
iron
salt, baking soda,
sugar
15. Classify each of the following as either a
heterogeneous or homogeneous mixture.
a. tap water
homogeneous
b. air
homogeneous
c. raisin muffin
heterogeneous
16. Compare mixtures and substances.
Substances have a constant composition, mixtures
do not. Each substance in a mixture retains
its own properties, whereas the properties of
a substance are different from those of the
elements that comprise it.
Solutions Manual
Section 3.4 Elements and
Compounds
pages 84–90
Practice Problems
page 88
19. A 78.0-g sample of an unknown compound
contains 12.4 g of hydrogen. What is the percent
by mass of hydrogen in the compound?
Percent by masshydrogen mass
__
100
mass
Percent by masshydrogen 12.4 g
_
100 15.9%
hydrogen
compound
78.0 g
Chemistry: Matter and Change • Chapter 3
37
3
SOLUTIONS MANUAL
20. If 1.0 g of hydrogen reacts completely with
19.0 g of fluorine, what is the percent by mass
of hydrogen in the compound that is formed?
masscompound 1.0 g 19.0 g 20.0 g
percent by masshydrogen mass
__
100
mass
percent by masshydrogen 1.0 g
_
100 5.0%
hydrogen
compound
20.0 g
21. If 3.5 g of X reacts with 10.5 g of Y to form the
compound XY, what is the percent by mass of X
in the compound? The percent by mass of Y?
massXY 3.50 g 10.5 g 14.0 g
percent by massX percent by massX
mass
_
100
mass
X
XY
3.50 g
_ 100 25% X
14.0 g
_
massY
100
percent by massY massXY
percent by massY
10.5 g
_ 100 75% X
14.0 g
22. Two unknown compounds are tested.
Compound I contains 15.0 g of hydrogen and
120.0 g of oxygen. Compound II contains
2.0 g of hydrogen and 32.0 g of oxygen. Are
the compounds the same?
Section 3.4 Assessment
page 90
24. Compare and contrast elements and
compounds.
Elements cannot be broken down into simpler
substances by ordinary chemical means, whereas
compounds can.
25. Describe the basic organizational feature of
the periodic table of elements.
The periodic table is organized by rows (called
“periods”) and columns (called “groups” or
“families”). Elements in the same group have similar
chemical and physical properties. The patterns of
similar properties repeat from period to period.
26. Explain how the law of definite proportions
applies to compounds.
The law of definite proportions describes the
mass composition of a substance.
27. State the type of compounds that are compared
in the law of multiple proportions?
The law of multiple proportions relates the
compositions of two compounds composed of the
same elements.
28. Complete the table, and then analyze the
Compound I: mass percentagehydrogen 15.0 g /(15.0 g 120.0 g) 11.1%
data to determine if Compounds I and II are
the same compound. If the compounds are
different, use the law of multiple proportions to
show the relationship between them.
Compound II: mass percentagehydrogen 2.0 g (2.0 g 32.0) 5.9%
Analysis Data of Two Iron Compounds
Because the mass compositions of the compounds
are different, the compounds themselves must be
different.
Compound
Total
Mass (g)
Mass
Fe (g)
Mass
O (g)
Mass
% Fe
Mass
%O
I
75.00
52.46
22.54
69.05
30.05
II
56.00
43.53
12.47
77.73
22.27
23. Challenge All you know about two unknown
compounds is that they have the same percent
by mass of carbon. With only this information,
can you be sure the two compounds are the
same? Explain.
No, you cannot be sure. Having the same
mass percentage of a single element does
not guarantee that the composition of each
compound is the same.
38
Chemistry: Matter and Change • Chapter 3
Compound I mass percent Fe 69.95%; mass percent
O 30.05%. Compound II mass percent Fe 77.73%;
mass percent O 22.27%. The compounds are not the
same.
Compound I: Fe:O 52.46 g/22.54 g 2.327
Compound II, Fe:O 43.53 g/12.47 g 3.491.
The relative mass ratio of Fe in compound I and
compound II is 2.327:3.491 ⫽ 0.667 ⫽ 2:3.
Solutions Manual
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CHAPTER
CHAPTER
3
SOLUTIONS MANUAL
29. Calculate the mass percent of hydrogen in
water and the mass percent of oxygen in water.
Mass % of hydrogen in water 20
100% 11%
100
_
Mass % of oxygen in water 160
_
100% 89%
180
30. Graph Create a graph that illustrates the law of
multiple proportions.
Graph should be similar to Figure 3.20.
a
Compound I
Mass (g)
2.000
Chapter 3 Assessment
pages 94–97
Section 3.1
Mastering Concepts
31. List three examples of substances. Explain why
each is a substance.
Answers will vary. Water, salt, and sugar are all
substances. Each is a substance because it has a
unique and unchanging composition.
32. Is carbon dioxide gas a pure substance?
Explain.
Yes. Carbon dioxide has a constant composition.
Cu
33. List at least three physical properties of water.
Cl
1.000
Answers will vary. Water is odorless, colorless, a
liquid, freezes at approximately 0°C, and boils at
approximately 100°C.
34. Identify each of the following as an extensive
b
Compound II
Mass (g)
1.000
intensive
Cu
Cl
b. mass
extensive
c. density
intensive
c
Mass Ratio
Comparison
2.000
Mass (g)
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
2.000
or intensive physical property.
a. melting point
d. length
extensive
I
35. “Properties are not affected by changes in
1.000
II
temperature and pressure.” Is this statement true
or false? Explain.
The statement is false. Properties are affected by
changes in temperature, pressure. For example,
the phase of a substance is determined by
its temperature and pressure. Other specific
examples will vary.
Solutions Manual
Chemistry: Matter and Change • Chapter 3
39
CHAPTER
3
36. List the three states of matter and give an
example for each state. Differentiate between a
gas and a vapor.
Solid (ice), liquid (water), and gas (helium).
Substances that are in the gas phase at room
temperature are referred to as gases, whereas
substances such as water vapor that are not gases
at room temperature are vapors.
Vapors of volatile solvents such as acetone and
methanol escape if the solvent is left opened at
room temperature.
37. Classify each as either solid, liquid, or gas at
room temperature.
a. milk
liquid
b. air
gas
c. copper
SOLUTIONS MANUAL
e. silver tarnishes
chemical
f. mercury is a liquid at room temperature
physical
39. A carton of milk is poured into a bowl.
Describe the changes that occur in the milk’s
shape and volume.
The volume of the milk remains unchanged. Milk,
which is a liquid, conforms to the shape of its
container, thus the shape of the milk changes as it
is poured from the carton into the bowl.
40. Boiling Water At what temperature would
250 mL of water boil? 1000 mL? Is the boiling
point an intensive or extensive property?
Explain.
100°C. 100°C. Boiling point is an intensive
property since it is independent of quantity or
amount.
d. helium
gas
e. diamond
solid
f. candle wax
solid
38. Classify each as a physical property or a
chemical property.
a. aluminum has a silvery color
physical
b. gold has a density of 19 g/cm3
physical
c. sodium ignites when dropped in water
chemical
Mastering Problems
41. A scientist is given the task of identifying an
unknown compound on the basis of its physical
properties. The substance is a white solid at
room temperature. Attempts to determine
its boiling point were unsuccessful. Using
Table 3.6, name the unknown compound.
Physical Properties of Common Substances
Substance
Color
State at
25°C
Boiling Point
(°C)
Oxygen
colorless
gas
⫺183
Water
colorless
liquid
100
Sucrose
white
solid
decomposes
Sodium chloride
white
solid
1413
Table 3.6 shows two compounds that are white
solids. Sucrose decomposes before a boiling point is
determined. Therefore, the unknown substance is
sucrose.
d. water boils at 100°C
physical
40
Chemistry: Matter and Change • Chapter 3
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solid
CHAPTER
3
Section 3.2
SOLUTIONS MANUAL
47. Salt Sodium and chlorine combine to form
Mastering Concepts
42. Label each set of diagrams in Figure 3.22 as
physical or chemical change.
sodium chloride. List the reactants and products
of this reaction.
Sodium and chlorine are the reactants, while
sodium chloride is the product formed. Iron oxygen 0 iron oxide.
48. Burning Candle After burning for three
hours, a candle has lost half of its mass. Explain
why this example does not violate the law of
conservation of mass.
The mass of the candle is conserved if you
consider the gaseous products from the reaction.
a. physical
b. chemical
43. Classify each as a physical change or a
chemical change.
a. breaking a pencil in two
physical
b. water freezing and forming ice
physical
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
c. frying an egg
chemical
d. burning wood
chemical
e. leaves turning color in the fall
chemical
44. Ripening Is the process of the ripening a
chemical or physical change? Explain.
It is a chemical change. A green banana has
different properties compared to a yellow banana.
45. Is a change in phase a physical or a chemical
change?
It’s a physical change. The composition of the
substance does not change.
46. List four indicators that a chemical change has
probably taken place.
49. Describe the difference between a physical
change and a chemical change.
A physical change alters a substance without
changing its composition, while a chemical
change involves a change in composition.
Mastering Problems
50. Ammonia Production A 28.0-g sample of
nitrogen gas combines completely with 6.0 g
of hydrogen gas to form ammonia. What is the
mass of ammonia the formed?
massnitrogen masshydrogen massammonia
massammonia 28.0 g 6.0 g 34.0 g
51. A 13.0-g sample of X combines with a 34.0-g
sample of Y to form the compound XY2. What
is the mass of the reactants?
X and Y are the reactants. The formula of the
compound formed is not important.
massreactants massproducts 13.0 g 34.0 g 47.0 g
52. If 45.98 g of sodium combines with an excess
of chlorine gas to form 116.89 g sodium chloride, what mass of chlorine gas is used in the
reaction?
masssodium masschlorine masssodium
masschlorine masssodium
chloride
chloride
masssodium
masschlorine 116.89 g – 45.98 g 70.91 g
Probable indicators of a chemical reaction include
a change in color, odor, or temperature, and/or
the production of a gas or a solid upon mixing.
Solutions Manual
Chemistry: Matter and Change • Chapter 3
41
CHAPTER
3
53. A substance breaks down into its component
elements when it is heated. If 68.0 g of the
substance is present before it is heated, what is
the combined mass of the component elements
after heating?
SOLUTIONS MANUAL
57. Name the separation method illustrated in
Figure 3.23.
massreactants massproducts 68.0 g
Regardless of what the compound decomposes
into, mass must be conserved.
54. Copper sulfide is formed when copper and
masssulfur used in the reaction initial mass of sulfur mass remaining after reaction
masssulfur masssulfur used in the reaction 41 g 9 g 32 g
masscopper sulfide masscopper masssulfur 127 g 32 g 159 g
55. When burning 180 grams of glucose in the
presence of 192 grams of oxygen, water and
carbon dioxide are produced. If 108 grams of
water are produced; how many grams of CO2
are produced?
massglucose massoxygen masscarbon dioxide
masswater
180 g 192 g 108 g masscarbon dioxide
masscarbon dioxide 264 g.
Section 3.3
Mastering Concepts
56. Describe the characteristics of a mixture.
Mixtures are a physical blend of two or more
substances in any proportion. Mixtures do not
have a constant composition. The properties of
the mixture are largely those of its component
substances.
42
Chemistry: Matter and Change • Chapter 3
distillation
58. Describe a method that could be used to
separate each of the following mixtures.
a. iron filings and sand
A magnet can be used to draw the iron filings
from the sand.
b. sand and salt
Add water to the mixture to dissolve the salt.
Filter the mixture to remove the sand, and then
boil off the water so only the salt remains.
c. the components of ink
Paper chromatography should be used
to separate the components of the ink. If
enough ink is available, distillation may also
be used, but is far more complicated than
chromatography.
d. helium and oxygen gases
Cool the gas mixture until it condenses, then
distill the condensate.
59. “A mixture is the chemical bonding of two
or more substances in any proportion.” Is this
statement true or false. Explain.
The statement is false because mixtures are
physical blends of substances, not a chemical
bonding of substances.
Solutions Manual
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sulfur are heated together. In this reaction,
127 g of copper reacts with 41 g of sulfur. After
the reaction is complete, 9 g of sulfur remains
unreacted. What is the mass of copper sulfide
formed?
CHAPTER
3
60. Which of the following are the same and which
are different?
a. a substance and a pure substance
same
b. a heterogeneous mixture and a solution
different
c. a substance and a mixture
different
d. a homogeneous mixture and a solution
same
61. Describe how a homogeneous mixture differs
from a heterogeneous mixture.
Homogeneous mixtures contain a single phase.
Heterogeneous mixtures may have many phases.
62. Seawater is composed of salt, sand and water.
Is seawater a heterogeneous or homogeneous
mixture? Explain.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Heterogeneous mixture. Composition is not
uniform.
63. Iced Tea Use iced tea with and without ice
cubes as examples to explain homogeneous
and heterogeneous mixtures. If you allow all
of the ice cubes to melt, what type of mixture
remains?
Iced tea with ice cubes is a heterogeneous
mixture.
Iced tea without ice cubes is a homogeneous
mixture.
When all ice cubes melt the remaining mixture is
homogeneous.
64. Chromatography What is chromatography
and how does it work?
Chromatography is a technique used to separate
components of a mixture.
SOLUTIONS MANUAL
Section 3.4
Mastering Concepts
65. State the definition of element.
An element is a substance that cannot be broken
down into simpler substances by physical or
chemical means.
66. Correct the following statements:
a. An element is a combination of two or more
compounds.
A compound is combination of two or more
elements.
b. When a small amount of sugar is completely
dissolved in water, a heterogeneous solution
is formed.
When a small amount of sugar is completely
dissolved in water, a homogeneous solution is
formed.
67. Name the elements contained in the following
compounds.
a. sodium chloride (NaCl)
sodium and chlorine
b. ammonia (NH3)
nitrogen and hydrogen
c. ethanol (C2H6O)
carbon, hydrogen, and oxygen
d. bromine (Br2)
bromine
68. What was Dmitri Mendeleev’s major contribu-
tion to the field of chemistry?
Mendeleev developed the first widely accepted
periodic table of elements.
69. Is it possible to distinguish between an element
and a compound? Explain.
Yes, elements can be distinguished from
compounds. Compounds can be broken down
into their component elements, whereas elements
cannot be broken down into simpler substances.
Solutions Manual
Chemistry: Matter and Change • Chapter 3
43
3
SOLUTIONS MANUAL
70. How are the properties of a compound related
to those of the elements that comprise it?
The properties of a compound are unique to that
compound and are different from those of its
component elements.
71. Which law states that a compound always
contains the same elements in the same proportion by mass?
The law of definite proportions
72. a. What is the percent by mass of carbon in
44 grams of carbon dioxide, CO2?
Percent by mass _
mass
__
100
mass
carbon
carbon dioxide
12 g
100 27%
44 g
b. What is the percent by mass of oxygen in
44 grams of carbon dioxide, CO2?
Percent by mass mass
__
100
mass
32 g
_
100 73%
oxyegn
carbon dioxide
44 g
or (100% 27% 73% ) if you use the result
from part (a)
73. Complete Table 3.7 by classifying the
following compounds as: 1:1 or 2:2, 1:2 or
2:1, and 1:3 or 3:1.
Ratios of Elements in Compounds
Compound
Simple Whole-Number Ratios
of Elements
NaCl
1:1
CuO
1:1
H2O
2:1
H2O2
2:2
magnesium oxide. If 10.57 g of magnesium reacts
completely with 6.96 g of oxygen, what is the
percent by mass of oxygen in magnesium oxide?
Mass percentageoxygen 6.96 g/(10.57 g 6.96 g)
39.7%
76. When mercury oxide is heated, it decomposes
into mercury and oxygen. If 28.4 g of mercury
oxide decomposes, producing 2.0 g of oxygen,
what is the percent by mass of mercury in
mercury oxide?
Mass Percentagemercury mass
__
100
mass
mercury
mercury oxide
__
28.4 g 2.0 g
93.0%
28.3 g 100
77. Carbon reacts with oxygen to form two
different compounds. Compound I contains
4.82 g of carbon for every 6.44 g of oxygen.
Compound II contains 20.13 g of carbon for
every 53.7 g of oxygen. What is the ratio of
carbon to a fixed mass of oxygen for the two
compounds?
Compound
massC
(g)
massO
(g)
massC/massO
I
4.82
6.44
4.82 g/6.44 g ⫽ 0.748
II
20.13
53.7
20.13 g/53.7 g ⫽ 0.375
(mass ratiocompound I/mass ratiocompound II)
(0.748/0.375) 1.99 ~2
The ratio of carbon to a fixed mass of oxygen
in compound I is 0.748:1, while in compound II
it is 0.375:1. The ratio of carbon to oxygen in
Compound I is twice that in Compound II.
78. A 100-g sample of an unknown salt contains
Mastering Problems
74. A 25.3-g sample of an unknown compound
contains 0.8 g of oxygen. What is the percent
by mass of oxygen in the compound?
Mass Percentageoxygen 75. Magnesium combines with oxygen to form
64 g of chlorine. What is the percent by mass of
chlorine in the compound?
Mass Percentagechlorine 64 g
_
100 64%
mass
__
100
mass
chlorine
compound
100 g
mass
__
100 mass
oxygen
compound
0.8 g
_
100 3%
25.3 g
44
Chemistry: Matter and Change • Chapter 3
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CHAPTER
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3
SOLUTIONS MANUAL
79. Which law would you use to compare CO and
heterogeneous.
a. brass (an alloy of zinc and copper)
The law of multiple proportions. CO2 will have
the highest percent by mass of oxygen because it
has more oxygen atoms for the same number of
carbon atom.
b. a salad
Compound
Mass
% of
Oxygen
Mass of
Second
Element
in the
Compound
(g)
CuO
80.0
16
20
64
H2O
18.0
16
89
2
H2O2
34.0
32
94
2
CO
28.0
16
57
12
CO2
44.0
32
73
12
Mixed Review
81. Which state(s) of matter are compressible?
Which state(s) of matter are not compressible?
Explain.
Gases are the most compressible state of
matter, solids the least. Liquids are virtually
incompressible. Compressibility is determined by
the amount of space between particles in each
state. Gases have the greatest amount of space
between particles, solids the least.
Solutions Manual
heterogeneous
c. blood
d. powdered drink mix dissolved in water
Elements in Compounds
Mass of
Mass of
Compound Oxygen
(g)
(g)
homogeneous
heterogeneous
80. Complete Table 3.8.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
82. Classify each mixture as homogeneous or
CO2? Explain. Without doing any calculation,
which of the two compounds CO and CO2 has
the highest percent by mass of oxygen in the
compound.
homogeneous
83. Phosphorus combines with hydrogen to
form phosphine. In this reaction, 123.9 g of
phosphorus combines with excess hydrogen
to produce 129.9 g of phosphine. After the
reaction, 310 g of hydrogen remains unreacted.
What mass of hydrogen is used in the reaction?
What was the initial mass of hydrogen before
the reaction?
Masshydrogen 129.9 g 123.9 g 6.0 g
Initial masshydrogen 310 g 6.0 g 316 g
84. If you have 100 particles of hydrogen and
100 particles of oxygen, how many units of
water can you form? Will you use all the
particles of both elements? If not, what will
remain?
50 units of water can be formed.
No, 50 particles of oxygen will remain.
Chemistry: Matter and Change • Chapter 3
45
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3
SOLUTIONS MANUAL
85. Classify each substance as a pure substance,
88. Ice Cream You might have noticed that while
a homogeneous mixture, or a heterogeneous
mixture.
a. air
eating ice cream on a very hot day some of
the ice cream begins to melt. Are the observed
changes in the state of the ice cream a physical
or chemical change? Justify your answer.
homogeneous mixture
b. aerosol
heterogeneous mixture
c. soil
homogeneous or heterogeneous mixture
depending on the soil sample
d. water
pure substance
e. sediment
heterogeneous mixture
f. muddy water
Ice cream melting is a physical change since the
chemical composition remains constant.
89. Pizza Is pizza a homogeneous or heteroge-
neous mixture? Explain.
A pizza is a heterogeneous mixture because
the individual parts of the pizza–dough, sauce,
cheese, toppings–remain separate.
90. Sodium reacts chemically with chlorine to form
sodium chloride. Is sodium chloride a mixture
or a compound?
Sodium chloride is a compound because it is a
substance composed of the two elements sodium
and chlorine, and it is formed by a chemical
reaction.
heterogeneous mixture
91. Is air a solution or heterogeneous mixture?
heterogeneous mixture, a compound, or an
element.
a. Pure drinking water—compound
b. Salty water—homogenous mixture
c. Helium—element
d. Seawater—heterogeneous mixture
e. Air—homogenous mixture
87. Cooking List physical properties of eggs
before and after they are cooked. Based on
your observations, does a physical change or
chemical change occur when eggs are cooked?
Justify your answer.
What technique can be used to separate air into
its components?
Air is a solution. Air can be separated into its
components, oxygen, nitrogen and carbon
dioxide by using gas chromatography.
92. Does the combination of the following elements
yield a compound or a mixture:
a. H2(g) ⫹ O2(g) 0 Water
compound
b. N2(g) ⫹ O2(g) 0 Air
mixture
Eggs before cooking: liquid, white (clear) and
bright yellow
Eggs after cooking: solid opaque white and dull
yellow
Chemical change.
46
Chemistry: Matter and Change • Chapter 3
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Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
86. Indicate each as a homogenous mixture, a
3
CHAPTER
SOLUTIONS MANUAL
Think Critically
95. Analyze Is gas escaping from an opened
93. Interpret Data A compound contains
elements X and Y. Four samples with different
masses were analyzed, and the masses of X
and Y in each sample were plotted on a graph
shown in Figure 3.24. The samples are labeled
I, II, III, and IV.
Mass of X (g)
96. Apply Give examples of heterogeneous
mixtures for the systems listed in Table 3.9.
Heterogeneous Mixtures
30
System
III
20
10
I
0
2
4
Example
Liquid-liquid
Water and oil
Solid-liquid
Sand and water
Solid-solid
Iron filings and sugar
II
IV
6
8
10
Mass of Y (g)
a. Which samples are from the same
compound? How do you know?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Physical change. The composition of CO2 gas is
the same inside and outside of the soft drink.
Masses of Elements
40
0
soft drink an example of chemical or physical
change? Explain.
Samples I, III, and IV are the same compound.
A straight line can be drawn through these
three plotted points. The slope of the line is
equivalent to ratio MassX/MassY. The fact that
all three points are on the same line shows
that they all have the same mass ratio of X to
Y and must be the same compound.
b. What is the approximate ratio of mass X
to mass Y in the samples that are from the
same compound?
Mass ratio of X to Y for samples I, III, and IV is
3.75:1.
c. What is the approximate ratio of mass X to
mass Y in the sample(s) that are not from
the same compound?
Sample II mass ratio is 1.9:1
94. Apply Air is a mixture of many gases,
primarily nitrogen, oxygen, and argon. Could
distillation be used to separate air into its
component gases? Explain.
Challenge Problem
97. A sample of a certain lead compound contains
6.46 grams of lead for each gram of oxygen.
A second sample has a mass of 68.54 g and
contains 28.76 g of oxygen. Are the two
samples the same?
Sample I: masslead/massoxygen 6.46
Sample II: masslead/massoxygen
(68.54 g 28.76 g)/28.76 g 1.383
The two samples are not the same because the
two masslead/massoxygen ratios are not the same.
Cumulative Review
98. What is chemistry? (Chapter 1)
Chemistry is the study of matter and the
changes that it undergoes.
99. What is mass? Weight? (Chapter 1)
Mass is the measure of the amount of matter
an object contains. It is measured on a balance.
The weight of an object is the amount of
gravitational pull acting on the mass of an
object. It is measured on a scale.
Yes. If the mixture of gases is cooled sufficiently,
it will condense into a mixture of liquids. This
mixture could then be distilled.
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Chemistry: Matter and Change • Chapter 3
47
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CHAPTER
SOLUTIONS MANUAL
100. Express the following in scientific notation.
(Chapter 2)
a. 34,500
103. Graph the data in Table 3.10. What is the
slope of the line? (Chapter 2)
Energy Released by Carbon
3.45 104
Mass (g)
Energy Released (kJ)
1.00
33
2.00
66
3.00
99
4.00
132
b. 2665
2.665 103
c. 0.9640
9.640 101
Energy Released by Carbon
d. 789
140
7.89 102
120
7.56 104
f. 0.002189
2.189 103
101. Perform the following operations. (Chapter 2)
a. 107 ⫻ 103
Energy released (kJ)
e. 75,600
100
80
60
40
1010
7.1 108
c. (2 ⫻
10⫺3)
20
0
⫻ (4 ⫻
105)
8 102
0
1.00
2.00
3.00
Mass (g)
4.00
Slope: 33 kJ/g
102. Convert 65°C to kelvins. (Chapter 2)
273 65°C 338 K
Writing in Chemistry
104. Synthetic Elements Select a synthetic
element, and prepare a short written report
on its development. Be sure to discuss recent
discoveries, list major research centers that
conduct this type of research, and describe the
properties of the synthesized element.
Student answers will vary. Students can obtain
some information on the elements from the
Merck Index or the CRC Handbook of Chemistry
and Physics.
48
Chemistry: Matter and Change • Chapter 3
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Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
b. (1.4 ⫻ 10⫺3) ⫻ (5.1 ⫻ 10⫺5)
CHAPTER
3
SOLUTIONS MANUAL
Document-Based Questions
Pigments Long before scientists understood the
properties of elements and compounds, artists used
chemistry to create pigments from natural materials.
Table 3.11 gives some examples of such pigments
used in ancient times.
Data obtained from: Orna, Mary Virginia. 2001. Chemistry,
color, and art. Journal of Chemical Education 78 (10): 1305
Common Artists’ Pigments
Used in Early Times
Common
Name
Chemical Identity
Comments
elemental carbon
(carbon black)
produced by dry
distillation of wood in
a closed vessel
calcium copper
tetrasilicate,
CaCuSi4O10
crystalline compound
containing some glass
impurity
Indigo
indigotin,
C16H10N202
derived from different
plants of the genus
indigofera
Iron
oxide
red
Fe2O3
in continuous use in
all geographic regions
and time periods
Verdigris
dibasic acetate of
copper
Cu(C2H3O2)2
• 2Cu(OH)2
other copper
compounds, including
carbonate, are also
called verdigris.
Charcoal
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Egyptian
blue
105. a. Determine the mass percent of carbon in
charcoal, indigo and verdigris.
Charcoal: mass percentcarbon 100%
Indigo: mass percentcarbon 73%
Verdigris: mass percentcarbon 14%
b. Determine the mass percent of oxygen in
iron oxide and Egyptian blue.
Iron oxide: mass percentoxygen 30%,
Egyptian blue: mass percentoxygen 43%
106. List an example of an element and a
107. Is the process of charcoal production from
the dry distillation of dry wood a chemical or
physical change? Explain.
Chemical change. The composition of the dry
wood changes into that of charcoal.
Standardized Test Practice
pages 98–99
Mass Analysis of Two Chlorine-Fluorine
Samples
Mass of
Chlorine
(g)
Mass of
Fluorine
(g)
I
13.022
II
5.753
Sample
% Cl
%F
6.978
65.11
34.89
9.248
?
?
Multiple Choice
1. What are the values for % Cl and % F,
respectively, for Sample II?
a. 0.6220 and 61.65
b. 61.65 and 38.35
c. 38.35 and 0.6220
d. 38.35 and 61.65
d
%Cl %F 5.753 g
__
100 38.35%
5.753 g 9.248 g
9.248 g
__
100 61.65%
5.753 g 9.248 g
2. Which statement best describes the relationship
between the two samples?
a. The compound in Sample I is the same as
in Sample II. Therefore, the mass ratio of
Cl to F in both samples will obey the law of
definite proportions.
b. The compound in Sample I is the same as
in Sample II. Therefore, the mass ratio of
Cl to F in both samples will obey the law of
multiple proportions.
compound from Table 3.11.
Element—C and compound —Fe2O3
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Chemistry: Matter and Change • Chapter 3
49
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3
c. The compound in Sample I is not the same
SOLUTIONS MANUAL
Use the diagram below to answer Questions 6 and 7.
as in Sample II. Therefore, the mass ratio of
Cl to F in both samples will obey the law of
definite proportions.
d. The compound in Sample I is not the same
as in Sample II. Therefore, the mass ratio of
Cl to F in both samples will obey the law of
multiple proportions.
A
B
C
6. Which best describes Figure A?
d
3. After two elements react to completion in a
closed container, the ratio of their masses in
the container will be the same as before the
reaction. Which law describes this principle?
a. law of definite proportions
b. law of multiple proportions
c. law of conservation of mass
d. law of conservation of energy
c
a.
b.
c.
d.
element
mixture
solution
compound
d
7. Which statement is false?
a. Figure B is composed of two different
compounds.
b. Figure C is composed of two different
a. forms solid crystals at room temperature
b. appears a white crystals
c. breaks down into carbon and water vapor
when heated
d. tastes sweet
c
5. Which describes a substance that is in the solid
state?
a. Its particles can flow past one another.
b. It can be compressed into a smaller volume.
c. It takes the shape of its container.
d. Its particles of matter are close together.
compounds.
c. Figure B represents 13 total atoms.
d. Three different types of elements are
represented in Figure C.
b
8. Na, K, Li, and Cs all share similar chemical
properties. In the periodic table of elements,
they most likely belong to the same
a. row.
b. period.
c. group.
d. element.
c
d
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Chemistry: Matter and Change • Chapter 3
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4. Which is NOT a physical property of table sugar?
CHAPTER
3
9. Magnesium reacts explosively with oxygen to
form magnesium oxide. Which is NOT true of
this reaction?
a. The mass of magnesium oxide produced
equals the mass of magnesium consumed
plus the mass of oxygen consumed.
b. The reaction describes the formation of a
new substance.
c. The product of the reaction, magnesium
oxide, is a chemical compound.
d. Magnesium oxide has physical and chemical
properties similar to both oxygen and
magnesium.
d
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Short Answer
10. Compare and contrast the independent variable
in an experiment with the dependent variable.
Both the independent and the dependent
variables can have different values during the
course of an experiment. The independent
variable has specific values that are
predetermined by the researcher, while the
dependent variable has values that are measured
as a result of the experiment and therefore
cannot be determined in advance.
11. A student reports the melting point of a gas as
⫺295°C. Explain why his claim is unlikely to
be correct.
The value of −295°C is equivalent to −22 K. This
answer does not make sense because 0 K is
absolute zero and no temperature can be below
this.
12. Place the following metric prefixes in order
from the smallest value to the largest value:
deci, kilo, centi, micro, mega, milli, giga, nano.
SOLUTIONS MANUAL
Extended Response
Use the table below to answer Questions 13 to 15.
Selected Properties of Substances in
a Mixture
Item
Soluble Soluble in Density Particle
in Water? Alcohol? (g/cm 3) Size (mm)
Sawdust
no
no
0.21
1
Mothball
flakes
no
yes
1.15
3
Table
salt
yes
no
2.17
2
13. Is the mixture described in the table homo-
geneous or heterogeneous? Explain how you
can tell.
The mixture is heterogeneous. Based on particle
size and color, the different substances can be
readily distinguished.
14. Do the data describe chemical or physical prop-
erties? Explain your answer.
These are physical properties because they
depend only on the substance itself. Chemical
properties depend on the behavior of substances
as they react with other substances.
15. Propose a method to separate the three
substances based on the properties described
above.
Use the solubility of mothballs in alcohol first:
dissolve the mothballs and filter or decant the
liquid. Use crystallization to remove the alcohol.
Next, add water to the remaining substances: the
sawdust will float since its density is less than
that of water, and the salt will dissolve. Filter or
decant to separate the two substances. Crystallize
the salt to remove the water.
nano, micro, milli, centi, deci, kilo, mega, giga
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Chemistry: Matter and Change • Chapter 3
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16. Explain the difference between a chemical
change and a physical change. Is the combustion of gasoline a chemical change or a physical
change? Explain your answer.
A physical change does not change the
composition of the substance, whereas a chemical
change is a process in which one or more
substances are changed into new substances.
The combustion of gasoline is a chemical change
because the gasoline is changed into other
substances during combustion.
SOLUTIONS MANUAL
Use the table below to answer Questions 18 and 19.
Percent by Mass of Carbon, Hydrogen, and
Oxygen in Selected Compounds
Compound
%H
%C
%O
Carbonic acid (H 2CO 3)
3.2
19.4
77.4
Acetic acid (CH 3COOH)
6.7
40.0
53.3
Methanol (CH 3OH)
12.5
37.5
40.0
Methanal (H 2CO)
6.7
40.0
53.3
Isopropanol (C 3H 8O)
13.3
60.0
26.7
18. You have a 125-g sample of one of these
17. Which is a correct statement about methods for
separating mixtures?
a. Distillation results in the formation of solid
particles of a dissolved substance.
b. Filtration depends on differences in sizes of
particles.
c. Separations depend on the chemical
properties of the substances involved.
d. Chromatography depends on the different
boiling points of substances.
e. Sublimation can be used to separate two
gases present in a mixture.
b
substances. You determine that it is made
of 16.7 g H, 75.0 g C, and 33.0 g O. Which
compound is it?
a. acetic acid
b. carbonic acid
c. methanal
d. methanol
e. isopropanol
e
19. In another experiment, you determine that a
sample of acetic acid consists of 56.8% oxygen.
What is your percent error?
a. 3.50%
b. 6.57%
c. 1.07%
d. 12.6%
e. 2.06%
b
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SAT Subject Test: Chemistry