Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
18 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
2
Practice Problems
24. Round each number to five significant figures. Write your
answers in scientific notation.
a. 0.000249950
b. 907.0759
c. 24,501,759
d. 300,100,500
25. Complete the following calculations. Round off your answers as
needed.
a. 52.6 g ϩ 309.1 g ϩ 77.214 g
b. 927.37 mL Ϫ 231.458 mL
c. 245.01 km ϫ 2.1 km
d. 529.31 m Ϭ 0.9000 s
2.4 Representing Data
A graph is a visual display of data. Representing your data in
graphs can reveal a pattern if one exists. You will encounter several
different kinds of graphs in your study of chemistry.
Circle graphs A circle graph is used to show the parts of a fixed
whole. This kind of graph is sometimes called a pie chart because it
is a circle divided into wedges that look like pieces of pie. Each
wedge represents a percentage of the whole. The entire graph represents 100 percent.
Bar graphs A bar graph is often used to show how a quantity
varies with time, location, or temperature. In this situation, the quantity being measured appears on the vertical axis. The independent
variable—time, for example—appears on the horizontal axis.
Line graphs The points on a line graph represent the intersection
of data for two variables. The independent variable is plotted on the
horizontal axis. The dependent variable is plotted on the vertical
axis. The points on a line graph are connected by a best fit line,
which is a line drawn so that as many points fall above the line as
below it.
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18 Chemistry: Matter and Change
Solving Problems: A Chemistry Handbook
SOLVING PROBLEMS:
A CHEMISTRY HANDBOOK
CHAPTER
2
Practice Problems
24. Round each number to five significant figures. Write your
answers in scientific notation.
a. 0.000249950
b. 907.0759
c. 24,501,759
d. 300,100,500
25. Complete the following calculations. Round off your answers as
needed.
a. 52.6 g ϩ 309.1 g ϩ 77.214 g
b. 927.37 mL Ϫ 231.458 mL
c. 245.01 km ϫ 2.1 km
d. 529.31 m Ϭ 0.9000 s
2.4 Representing Data
A graph is a visual display of data. Representing your data in
graphs can reveal a pattern if one exists. You will encounter several
different kinds of graphs in your study of chemistry.
Circle graphs A circle graph is used to show the parts of a fixed
whole. This kind of graph is sometimes called a pie chart because it
is a circle divided into wedges that look like pieces of pie. Each
wedge represents a percentage of the whole. The entire graph represents 100 percent.
Bar graphs A bar graph is often used to show how a quantity
varies with time, location, or temperature. In this situation, the quantity being measured appears on the vertical axis. The independent
variable—time, for example—appears on the horizontal axis.
Line graphs The points on a line graph represent the intersection
of data for two variables. The independent variable is plotted on the
horizontal axis. The dependent variable is plotted on the vertical
axis. The points on a line graph are connected by a best fit line,
which is a line drawn so that as many points fall above the line as
below it.
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▲
▲