Chemistry: An Introduction to General, Organic, and
Biological Chemistry Exam Test Bank 13th Edition
by Karen Timberlake – Comprehensive Verified
Guide (2026)
1. How many significant figures are in 0.00405060?
a) 4
b) 5
c) 6
d) 8
Answer: c) 6
Rationale: Leading zeros are not significant. The digits
4,0,5,0,6,0 are all significant because captive zeros and
trailing zeros after a decimal point count.
2. The density of a substance is 2.70 g/mL. What is the
mass of 15.0 mL?
a) 0.180 g
b) 5.56 g
1
,c) 40.5 g
d) 405 g
Answer: c) 40.5 g
*Rationale: Mass = Density × Volume = 2.70 g/mL ×
15.0 mL = 40.5 g (three significant figures).*
3. Convert 25.0°C to Kelvin.
a) 248 K
b) 273 K
c) 298 K
d) 313 K
Answer: c) 298 K
*Rationale: K = °C + 273.15 = 25.0 + 273.15 =
298.15 K ≈ 298 K.*
4. A cylinder has a mass of 45.2 g and a volume of 12.0
mL. What is its density?
a) 0.266 g/mL
b) 3.77 g/mL
c) 33.2 g/mL
2
,d) 542 g/mL
Answer: b) 3.77 g/mL
*Rationale: Density = mass/volume = 45.2 g / 12.0 mL =
3.7666 ≈ 3.77 g/mL.*
5. Which of the following is an exact number?
a) 12 apples
b) 12.0 cm
c) 12.0 g
d) 12.0 mL
Answer: a) 12 apples
Rationale: Exact numbers come from counting, not
measurement. Measured quantities have uncertainty.
6. Round 0.007865 to three significant figures.
a) 0.00787
b) 0.00786
c) 0.0079
d) 0.008
Answer: a) 0.00787
3
, Rationale: The digits 7,8,6 are the first three significant
figures. The next digit is 5, round up 6 to 7.
7. What is the result of (3.22 × 0.0510) / 4.001?
a) 0.041
b) 0.0410
c) 0.0411
d) 0.04
Answer: b) 0.0410
*Rationale: 3.22 (3 SF) × 0.0510 (3 SF) = 0.16422 /
4.001 (4 SF) = 0.04104 → 0.0410 (3 SF).*
8. A rock displaces 8.2 mL of water and has a mass of
22.4 g. The density is:
a) 0.37 g/mL
b) 2.7 g/mL
c) 2.73 g/mL
d) 184 g/mL
Answer: b) 2.7 g/mL
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Biological Chemistry Exam Test Bank 13th Edition
by Karen Timberlake – Comprehensive Verified
Guide (2026)
1. How many significant figures are in 0.00405060?
a) 4
b) 5
c) 6
d) 8
Answer: c) 6
Rationale: Leading zeros are not significant. The digits
4,0,5,0,6,0 are all significant because captive zeros and
trailing zeros after a decimal point count.
2. The density of a substance is 2.70 g/mL. What is the
mass of 15.0 mL?
a) 0.180 g
b) 5.56 g
1
,c) 40.5 g
d) 405 g
Answer: c) 40.5 g
*Rationale: Mass = Density × Volume = 2.70 g/mL ×
15.0 mL = 40.5 g (three significant figures).*
3. Convert 25.0°C to Kelvin.
a) 248 K
b) 273 K
c) 298 K
d) 313 K
Answer: c) 298 K
*Rationale: K = °C + 273.15 = 25.0 + 273.15 =
298.15 K ≈ 298 K.*
4. A cylinder has a mass of 45.2 g and a volume of 12.0
mL. What is its density?
a) 0.266 g/mL
b) 3.77 g/mL
c) 33.2 g/mL
2
,d) 542 g/mL
Answer: b) 3.77 g/mL
*Rationale: Density = mass/volume = 45.2 g / 12.0 mL =
3.7666 ≈ 3.77 g/mL.*
5. Which of the following is an exact number?
a) 12 apples
b) 12.0 cm
c) 12.0 g
d) 12.0 mL
Answer: a) 12 apples
Rationale: Exact numbers come from counting, not
measurement. Measured quantities have uncertainty.
6. Round 0.007865 to three significant figures.
a) 0.00787
b) 0.00786
c) 0.0079
d) 0.008
Answer: a) 0.00787
3
, Rationale: The digits 7,8,6 are the first three significant
figures. The next digit is 5, round up 6 to 7.
7. What is the result of (3.22 × 0.0510) / 4.001?
a) 0.041
b) 0.0410
c) 0.0411
d) 0.04
Answer: b) 0.0410
*Rationale: 3.22 (3 SF) × 0.0510 (3 SF) = 0.16422 /
4.001 (4 SF) = 0.04104 → 0.0410 (3 SF).*
8. A rock displaces 8.2 mL of water and has a mass of
22.4 g. The density is:
a) 0.37 g/mL
b) 2.7 g/mL
c) 2.73 g/mL
d) 184 g/mL
Answer: b) 2.7 g/mL
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