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Practice Problems
Chang, Chapter 1
Chemistry: The Study of Change
1.7 Measurement
• A piece of platinum metal with a density of
21.5 g/cm3 has a volume of 4.49 cm3. What is
its mass?
Answer: 96.5 g
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1.7 Measurement
• The density of sulfuric acid in a certain car
battery is 1.41 g/ml. Calculate the mass of
242 mL of the liquid.
Answer: 341 g
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6.4 Enthalpy of Chemical Reactions
• Convert:
a) 327.5°C (the melting point of lead) to degrees Fahrenheit;
b) 172.9°F (the boiling point of ethanol) to degrees Celsius;
c) 77 K, the boiling point of liquid nitrogen, to degrees Celsius.
Answers: a) 621.5°F
b) 78.3°C
c) -196°C
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1.8 Handling Numbers
• Determine the number of significant figures in each of the
following measurements
a)
b)
c)
d)
e)
24 mL
3001 g
0.0320 m3
6.4 x 104 molecules
560 kg
Answer: a) 2
b) 4
c) 3
d) 2
e) 2
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1.8 Handling Numbers
• Carry out the following arithmetic operations &
round off the answers to the appropriate number of
significant figures:
a)
b)
c)
d)
e)
26.5862 L + 0.17 L
9.1 g – 4.682 g
7.1 x 104 dm x 2.2654 x 102 dm
6.54 g ÷ 86.5542 mL
(7.55 x 104 m) – ( 8.62 x 103 m)
Answers: a) 26.76 L
b) 4.4 g
c) 1.6 x 107 dm2
d) 0.0756 g/mL
e) 6.69 x 104 m
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1.9 Dimensional Analysis in Solving Problems
• A roll of aluminum foil has a mass of 1.07 kg.
What is its mass in pounds?
Answer: 2.36 lb.
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1.9 Dimensional Analysis in Solving Problems
• The volume of a room is 1.08 x 108 dm3.
What is the volume in m3?
Answer:1.08 x 105 m3
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1.9 Dimensional Analysis in Solving Problems
• The density of the lightest metal, lithium (Li),
is 5.34 x 102 kg/m3. Convert the density to
g/cm3.
Answer: 0.534 g/cm³
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