In Class Practice - Chapter 02
Name: ___________________________________________
Period: __________________________ Teacher: _________________________________________________________
2.1 Units of Measurement
 Base units - Complete the following table
Table 2-1
SI Base Units
Quantity
Base unit
second (s)
meter (m)
Kilogram (kg)
kelvin (K)
Mole (mol)
ampere (A)
candela (cd)
 Prefixes - Complete the following table
Prefixes Used with SI Units
Prefix
giga
Symbol
G
Factor
Scientific
notation
Example
1,000,000,000
109
gigameter (Gm)
megagram (Mg)
mega
M
1,000,000
106
kilo
k
1000
103
kilometer (km)
deciliter (dL)
deci
d
1/10
10-1
centi
c
1/100
10-2
centimeter (cm)
milligram (mg)
milli
m
1/1000
10-3
micro

1/1000000
10-6
microgram (mg)
1/1000000000
10-9
nanometer (nm)
10-12
picometer (pm)
nano
n
pico
p
1/1000000000000
Practice Problems
1. How many centigrams are in a gram?
2. How many liters are in a kiloliter?
3. How many nanoseconds are in a second?
4. How many meters are in a kilometer?
 Derived units
Practice Problems
5. Calculate the density of a piece of bone with a mass of 3.8 g and a volume of 2.0 cm 3.
6. A spoonful of sugar with a mass of 8.8 grams is poured into a 10-mL graduated
cylinder. The volume reading is 5.5 mL. What is the density of the sugar?
7. A 10.0-gram pat of butter raises the water level in a 50-mL graduated cylinder by 11.6
mL. What is the density of the butter?
8. A sample of metal has a mass of 34.65 g. When placed in a graduated cylinder
containing water, the water level rises
3.3 mL. Which of the following metals is the sample made from: silver, which has a
density of 10.5 g/cm3; tin, which has a density of 7.28 g/cm3; or titanium, which has a
density of
4.5 g/cm3?
9. Rock salt has a density of 2.18 g/cm3. What would the volume be of a 4.8-g sample of
rock salt?
10. A piece of lead displaces 1.5 mL of water in a graduated cylinder. Lead has a density of
11.34 g/cm3. What is the mass of the piece of lead?
 Temperature
Practice Problems
11. Convert each temperature reported in degrees Celsius to kelvins.
a. 54°C
b. -54°C
c. 15°C
12. Convert each temperature reported in kelvins to degrees Celsius.
a. 32 K
b. 0 K
c. 281 K
In Class Practice - Chapter 02
Name: ___________________________________________
Period: __________________________ Teacher: _________________________________________________________
2.2 Scientific Notation and Dimensional Analysis
 Scientific Notation
Practice Problems
13. Express the following quantities in scientific notation.
a. 50,000 m/s2
b. 0.00000000062 kg
c. 0.000023 s
d. 21,300,000 mL
e. 990,900,000 m/s
f. 0.000000004 L
 Adding and subtracting using scientific notation
Practice Problems
14. Solve the following addition and subtraction problems. Write your answers in
scientific notation.
a. 5.10x1020 + 4.11x1021
b. 6.20x108 - 3.0x106
c. 2.303x105 - 2.30x103
d. 1.20x10-4 + 4.7x10-5
e. 6.20x10-6 + 5.30x10-5
f. 8.200x102 - 2.0x10-1
 Multiplying and dividing using scientific notation
Practice Problems
15. Solve the following multiplication and division problems. Write your answers in
scientific notation.
a. (12x104 m) x (5x10-2 m)
b. (3x107 km) x (3x107 km)
c. (2x10-4 mm) x (2x10-4 mm)
d. (90x1014 kg) ÷ (9x1012 L)
e. (12x10-4 m) ÷(3x10-4 s)
f. (20x1015 km) ÷ (5x1011 s)
 Dimensional analysis
Practice Problems
16. Mount Everest is 8847 m high. How many centimeters high is the mountain?
17. Your friend is 1.56 m tall. How many millimeters tall is your friend?
18. A family consumes 2.5 gallons of milk per week. How many liters of milk do they need
to buy for one week?
(Hint: 1 L = 0.908 quart; 1 gallon = 4 quarts.)
19. How many hours are there in one week? How many minutes are there in one week?
In Class Practice - Chapter 02
Name: ___________________________________________
Period: __________________________ Teacher: _________________________________________________________
2.3 Uncertainty In Data
 Percent error
Practice Problems
20. Suppose you calculate your semester grade in chemistry as 90.1, but you receive a
grade of 89.4. What is your percent error?
21. On a bathroom scale, a person always weighs 2.5 pounds less than on the scale at the
doctor’s office. What is the percent error of the bathroom scale if the person’s actual
weight is 125 pounds?
22. A length of wood has a labeled length value of 2.50 meters. You measure its length
three times. Each time you get the same value: 2.35 meters.
a. What is the percent error of your measurements?
b. Are your measurements precise? Are they accurate?
 Significant figures
Practice Problems
23. Determine the number of significant figures in each measurement.
a. 0.000010 L
c. 2.4050x10-4 kg
b. 907.0 km
d. 300,100,000 g
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 + 309.1 g + 77.214 g
b. 927.37 mL - 231.458 mL
c. 245.01 km x 2.1 km
d. 529.31 m ÷ 0.9000 s
In Class Practice - Chapter 02
Name: ___________________________________________
Period: __________________________ Teacher: _________________________________________________________
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.
Example Problem 11
Calculating the Slope of a Line from Data Points
Calculate the slope of a line that contains these data points:
(3.0 cm3, 6.0 g) and (12 cm3, 24 g).
To calculate the slope of a line from data points, substitute the values into the following
equation.
slope 
slope 
y2  y1
x2  x1
 y/x
24 g  6.0 g
18 g

 2.0 g/cm 3
3
3
12 cm  3.0 cm
9.0 cm 3
Practice Problems
26. Calculate the slope of each line using the points given.
a. (24 cm3, 36 g), (12 cm3, 18 g)
b. (25.6 cm3, 28.16 g), (17.3 cm3, 19.03 g)
c. (15s, 147 m), (21 s, 205.8 m)
d. (55 kJ, 18.75°C), (75 kJ, 75.00°C)
 Interpreting data When you are asked to read the information from a graph, first
identify the dependent variable and the independent variable. Look at the ranges of the data
and think about what measurements were taken to obtain the data. Determine whether the
relationship between the variables is linear or nonlinear. If the relationship is linear,
determine if the slope is positive or negative.
If the points on the graph are connected, they are considered continuous. You can read
data that falls between the measured points. This process is called interpolation. You can
extend the line on a graph beyond the plotted points and estimate values for the variables.
This process is called extrapolation. Extrapolation is less reliable than interpolation because
you are going beyond the range of the data collected.
In Class Practice - Chapter 02
Name: ___________________________________________
Period: __________________________ Teacher: _________________________________________________________
Chapter 2 Review
27. Which SI units would you use to measure the following quantities?
a. the amount of water you drink in one day
b. the distance from New York to San Francisco
c. the mass of an apple
28. How does adding the prefix kilo- to an SI unit affect the quantity being described?
29. What units are used for density in the SI system? Are these base units or derived
units? Explain your answer.
30. Is it more important for a quarterback on a football team to be accurate or precise
when throwing the football? Explain.
31. A student takes three mass measurements. The measurements have errors of 0.42 g,
0.38 g, and 0.47 g. What information would you need to determine whether these
measurements are accurate or precise?
32. What conversion factor is needed to convert minutes to hours?
33. What kind of graph would you use to represent the following data?
a. the segments of the population who plan to vote for a certain candidate
b. the average monthly temperatures of two cities
c. the amount of fat in three different kinds of potato chips
d. the percent by mass of elements in Earth’s atmosphere
e. your scores on math quizzes during a year
f. the effect of a hormone on tadpole growth