Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
84 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER 9
Practice Problems
2. Write a balanced chemical equation for the following reactions,
making sure coefficients are in their lowest possible ratio.
a. Solid potassium reacts with liquid water to produce hydrogen gas and a water solution of potassium hydroxide.
b. Calcium chloride and sodium carbonate in water solution
produce solid calcium carbonate and a water solution of
sodium chloride.
c. Liquid bromine and solid lithium iodide react to form solid
lithium bromide and solid iodine.
9.2 Classifying Chemical Reactions
Reactions can be classified into various types. In a synthesis
reaction, two or more substances react to produce a single product.
An example is the reaction between the elements potassium and
bromine to form potassium bromide.
2K(s) ϩ Br 2 (l) 0 2KBr(s)
Synthesis reactions can also occur between compounds or between a
compound and an element. In a combustion reaction, oxygen combines with a substance and produces light and heat. The burning of
methane in oxygen is an example of a combustion reaction.
CH 4 (g) ϩ 2O 2 (g) 0 CO 2 (g) ϩ 2H 2 O(g)
Certain reactions may be examples of both synthesis and
combustion. An example is the burning of carbon.
C(s) ϩ O 2 (g) 0 CO 2 (g)
A decomposition reaction is one in which a single compound
breaks down into two or more elements or new compounds. An
example is the breakdown of aluminum oxide into aluminum and
oxygen gas.
2Al 2 O 3 (s) 0 4Al(s) ϩ 3O 2 (g)