Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
211
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 20
Lithium batteries A battery that oxidizes lithium at the anode
can generate a large voltage because of lithium’s low E 0 value
(Ϫ3.04 V). Lithium is also the lightest known metal. These properties of lithium make it desirable for use in lightweight batteries.
Lithium batteries last longer than other types of batteries, and they
are often used in devices such as watches, computers, and cameras.
Fuel cells A voltaic cell that uses the oxidation of a fuel to produce electricity is called a fuel cell. In a hydrogen–oxygen fuel cell,
hydrogen is oxidized and oxygen is reduced. The overall cell reaction is the same as the equation for the combustion of hydrogen to
form water.
2H 2 (g) ϩ O 2 (g) 0 2H 2 O(l)
The difference is that the reaction in a fuel cell is controlled so that
most of the chemical energy is converted to electrical energy instead
of heat. Fuel cells produce electricity as long as fuel is supplied to
them.
Practice Problems
4. What element is reduced in a standard automobile battery?
5. What term describes a battery that is not rechargeable?
6. What element is oxidized in most dry cells?
7. What is the product of the overall reaction in a hydrogen–
oxygen fuel cell?
Corrosion A redox reaction of a metal with its environment that
results in the deterioration of the metal is called corrosion. The
most common example is the rusting of iron, which occurs when air,
water, and iron set up a natural voltaic cell that causes iron atoms to
lose electrons. In the overall cell reaction, iron is oxidized and oxygen is reduced.
4Fe(s) ϩ 3O 2 (g) 0 2Fe 2 O 3 (s)
Various methods can be used to inhibit the corrosion of iron.
Applying a coat of paint can help to seal out air and moisture. Iron
can also be protected by placing it in contact with a piece of metal
such as aluminum that is more easily oxidized than iron. The aluminum corrodes while the iron is preserved. Finally, corrosion of
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▲
▲
Solving Problems: A Chemistry Handbook
Chemistry: Matter and Change
211
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 20
Lithium batteries A battery that oxidizes lithium at the anode
can generate a large voltage because of lithium’s low E 0 value
(Ϫ3.04 V). Lithium is also the lightest known metal. These properties of lithium make it desirable for use in lightweight batteries.
Lithium batteries last longer than other types of batteries, and they
are often used in devices such as watches, computers, and cameras.
Fuel cells A voltaic cell that uses the oxidation of a fuel to produce electricity is called a fuel cell. In a hydrogen–oxygen fuel cell,
hydrogen is oxidized and oxygen is reduced. The overall cell reaction is the same as the equation for the combustion of hydrogen to
form water.
2H 2 (g) ϩ O 2 (g) 0 2H 2 O(l)
The difference is that the reaction in a fuel cell is controlled so that
most of the chemical energy is converted to electrical energy instead
of heat. Fuel cells produce electricity as long as fuel is supplied to
them.
Practice Problems
4. What element is reduced in a standard automobile battery?
5. What term describes a battery that is not rechargeable?
6. What element is oxidized in most dry cells?
7. What is the product of the overall reaction in a hydrogen–
oxygen fuel cell?
Corrosion A redox reaction of a metal with its environment that
results in the deterioration of the metal is called corrosion. The
most common example is the rusting of iron, which occurs when air,
water, and iron set up a natural voltaic cell that causes iron atoms to
lose electrons. In the overall cell reaction, iron is oxidized and oxygen is reduced.
4Fe(s) ϩ 3O 2 (g) 0 2Fe 2 O 3 (s)
Various methods can be used to inhibit the corrosion of iron.
Applying a coat of paint can help to seal out air and moisture. Iron
can also be protected by placing it in contact with a piece of metal
such as aluminum that is more easily oxidized than iron. The aluminum corrodes while the iron is preserved. Finally, corrosion of
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▲
▲