CHEM 103 Modules 1-6 Exam Answers Portage Learning
Actual Exam 2026/2027 – Complete All-Module Bundle with
Detailed Rationales | 100% Verified | Pass Guaranteed – A+
Graded
SECTION A: MODULE 1 – MEASUREMENT, SIGNIFICANT FIGURES &
DIMENSIONAL ANALYSIS (Q1–Q20)
Q1: How many significant figures are in the measurement 0.00450 g?
A. 2
B. 3 [CORRECT]
C. 4
D. 5
Correct Answer: B
Rationale: Leading zeros are never significant, but trailing zeros after a decimal point
are, giving 4, 5, and 0 as the three significant figures; counting the leading zeros (4 or 5)
is the most common error.
Q2: What is the SI base unit for mass?
A. Gram
B. Liter
C. Kilogram [CORRECT]
D. Meter
Correct Answer: C
Rationale: The kilogram is the SI base unit of mass, even though the gram is used more
often in laboratory settings; the liter measures volume and the meter measures length.
Q3: A beaker contains 2.5 kg of sand. What is this mass in grams?
A. 0.0025 g
B. 25 g
C. 250 g
D. 2500 g [CORRECT]
Correct Answer: D
Rationale: Since 1 kg = 1000 g, multiplying 2.5 × 1000 gives 2500 g; dividing instead of
multiplying produces the error 0.0025 g.
,Q4: Express 0.00056 in proper scientific notation.
A. 5.6 × 10³
B. 5.6 × 10⁻⁴ [CORRECT]
C. 56 × 10⁻⁵
D. 5.6 × 10⁴
Correct Answer: B
Rationale: The decimal moves four places right to give 5.6, so the exponent is −4; a
positive exponent (10⁴ or 10³) describes numbers larger than one, and coefficients must
be between 1 and 10.
Q5: Perform the calculation and report with the correct number of significant figures:
12.11 + 18.0 + 1.013
A. 31.123
B. 31.12
C. 31.1 [CORRECT]
D. 31
Correct Answer: C
Rationale: In addition, the answer is rounded to the fewest decimal places (18.0 has
one), giving 31.1; reporting 31.123 or 31.12 retains unjustified precision.
Q6: Perform the calculation and report with the correct number of significant figures:
3.45 × 2.1
A. 7.245
B. 7.2 [CORRECT]
C. 7.25
D. 7
Correct Answer: B
Rationale: In multiplication, the answer carries the fewest significant figures (2.1 has
two), so 7.245 rounds to 7.2; keeping all four digits overstates the precision of the
measurement.
Q7: A metal block has a mass of 45.0 g and a volume of 15.0 mL. What is its density?
A. 0.333 g/mL
B. 675 g/mL
C. 30 g/mL
D. 3.00 g/mL [CORRECT]
Correct Answer: D
Rationale: Density = mass ÷ volume = 45.0 ÷ 15.0 = 3.00 g/mL; multiplying the values or
dividing in reverse order produces the incorrect answers.
,Q8: A student measures the density of aluminum as 2.85 g/mL; the accepted value is
2.70 g/mL. What is the percent error?
A. 1.5%
B. 15%
C. 5.6% [CORRECT]
D. 0.056%
Correct Answer: C
Rationale: Percent error = |2.85 − 2.70| ÷ 2.70 × 100 = 5.6%; forgetting to divide by the
accepted value gives 1.5%, and skipping × 100 gives 0.056.
Q9: Convert 25°C to Kelvin.
A. 298 K [CORRECT]
B. 248 K
C. 25 K
D. 198 K
Correct Answer: A
Rationale: K = °C + 273, so 25 + 273 = 298 K; subtracting 273 instead of adding gives
248 K, a common sign error.
Q10: Normal body temperature is 98.6°F. What is this in Celsius?
A. 20.0°C
B. 37.0°C [CORRECT]
C. 66.6°C
D. 45.0°C
Correct Answer: B
Rationale: °C = (°F − 32) × 5/9 = (98.6 − 32) × 5/9 = 37.0°C; forgetting to subtract 32 first
gives 54.8°C, and skipping the 5/9 factor gives 66.6°C.
Q11: A road sign lists a distance of 5.0 km. Using 1 km = 0.6214 mi, what is this
distance in miles?
A. 8.0 mi
B. 0.12 mi
C. 3.1 mi [CORRECT]
D. 31 mi
Correct Answer: C
Rationale: 5.0 km × 0.6214 mi/km = 3.1 mi (two significant figures); dividing instead of
multiplying gives 8.0 mi, and dropping a decimal place gives 31 mi.
Q12: Convert 0.750 kg to milligrams.
A. 0.00075 mg
, B. 750 mg
C. 7.50 × 10³ mg
D. 7.50 × 10⁵ mg [CORRECT]
Correct Answer: D
Rationale: 0.750 kg = 750 g, and 750 g × 1000 mg/g = 7.50 × 10⁵ mg; stopping at grams
(750 mg) or missing a factor of 1000 reflects incomplete metric conversion.
Q13: A car travels at 60 mi/hr. Given 1 mi = 1609 m, what is this speed in m/s?
A. 1.6 m/s
B. 26.8 m/s [CORRECT]
C. 96.5 m/s
D. 0.017 m/s
Correct Answer: B
Rationale: (60 × 1609) ÷ 3600 = 26.8 m/s; dividing by 60 only once (giving 96.5 or 1609)
reflects incomplete unit cancellation of hours to seconds.
Q14: A cube measures 2.0 cm on each side. What is its volume, reported correctly?
A. 8 cm³
B. 8.00 cm³
C. 8.0 cm³ [CORRECT]
D. 6.0 cm³
Correct Answer: C
Rationale: V = 2.0³ = 8.0 cm³, and multiplying/dividing requires the fewest significant
figures (2.0 has two), so the answer is 8.0 cm³; adding a cubed side instead of
multiplying gives 6.0.
Q15: A pencil is 30.5 cm long. Using 1 in = 2.54 cm, what is its length in inches?
A. 12.0 in [CORRECT]
B. 77.5 in
C. 1.20 in
D. 0.083 in
Correct Answer: A
Rationale: 30.5 cm ÷ 2.54 cm/in = 12.0 in; multiplying by 2.54 instead of dividing gives
77.5 in, a classic inverted-conversion-factor error.
Q16: The metric prefix "micro" (μ) represents which multiplier?
A. 10⁻³
B. 10⁻⁶ [CORRECT]
C. 10⁶
D. 10⁻⁹
Actual Exam 2026/2027 – Complete All-Module Bundle with
Detailed Rationales | 100% Verified | Pass Guaranteed – A+
Graded
SECTION A: MODULE 1 – MEASUREMENT, SIGNIFICANT FIGURES &
DIMENSIONAL ANALYSIS (Q1–Q20)
Q1: How many significant figures are in the measurement 0.00450 g?
A. 2
B. 3 [CORRECT]
C. 4
D. 5
Correct Answer: B
Rationale: Leading zeros are never significant, but trailing zeros after a decimal point
are, giving 4, 5, and 0 as the three significant figures; counting the leading zeros (4 or 5)
is the most common error.
Q2: What is the SI base unit for mass?
A. Gram
B. Liter
C. Kilogram [CORRECT]
D. Meter
Correct Answer: C
Rationale: The kilogram is the SI base unit of mass, even though the gram is used more
often in laboratory settings; the liter measures volume and the meter measures length.
Q3: A beaker contains 2.5 kg of sand. What is this mass in grams?
A. 0.0025 g
B. 25 g
C. 250 g
D. 2500 g [CORRECT]
Correct Answer: D
Rationale: Since 1 kg = 1000 g, multiplying 2.5 × 1000 gives 2500 g; dividing instead of
multiplying produces the error 0.0025 g.
,Q4: Express 0.00056 in proper scientific notation.
A. 5.6 × 10³
B. 5.6 × 10⁻⁴ [CORRECT]
C. 56 × 10⁻⁵
D. 5.6 × 10⁴
Correct Answer: B
Rationale: The decimal moves four places right to give 5.6, so the exponent is −4; a
positive exponent (10⁴ or 10³) describes numbers larger than one, and coefficients must
be between 1 and 10.
Q5: Perform the calculation and report with the correct number of significant figures:
12.11 + 18.0 + 1.013
A. 31.123
B. 31.12
C. 31.1 [CORRECT]
D. 31
Correct Answer: C
Rationale: In addition, the answer is rounded to the fewest decimal places (18.0 has
one), giving 31.1; reporting 31.123 or 31.12 retains unjustified precision.
Q6: Perform the calculation and report with the correct number of significant figures:
3.45 × 2.1
A. 7.245
B. 7.2 [CORRECT]
C. 7.25
D. 7
Correct Answer: B
Rationale: In multiplication, the answer carries the fewest significant figures (2.1 has
two), so 7.245 rounds to 7.2; keeping all four digits overstates the precision of the
measurement.
Q7: A metal block has a mass of 45.0 g and a volume of 15.0 mL. What is its density?
A. 0.333 g/mL
B. 675 g/mL
C. 30 g/mL
D. 3.00 g/mL [CORRECT]
Correct Answer: D
Rationale: Density = mass ÷ volume = 45.0 ÷ 15.0 = 3.00 g/mL; multiplying the values or
dividing in reverse order produces the incorrect answers.
,Q8: A student measures the density of aluminum as 2.85 g/mL; the accepted value is
2.70 g/mL. What is the percent error?
A. 1.5%
B. 15%
C. 5.6% [CORRECT]
D. 0.056%
Correct Answer: C
Rationale: Percent error = |2.85 − 2.70| ÷ 2.70 × 100 = 5.6%; forgetting to divide by the
accepted value gives 1.5%, and skipping × 100 gives 0.056.
Q9: Convert 25°C to Kelvin.
A. 298 K [CORRECT]
B. 248 K
C. 25 K
D. 198 K
Correct Answer: A
Rationale: K = °C + 273, so 25 + 273 = 298 K; subtracting 273 instead of adding gives
248 K, a common sign error.
Q10: Normal body temperature is 98.6°F. What is this in Celsius?
A. 20.0°C
B. 37.0°C [CORRECT]
C. 66.6°C
D. 45.0°C
Correct Answer: B
Rationale: °C = (°F − 32) × 5/9 = (98.6 − 32) × 5/9 = 37.0°C; forgetting to subtract 32 first
gives 54.8°C, and skipping the 5/9 factor gives 66.6°C.
Q11: A road sign lists a distance of 5.0 km. Using 1 km = 0.6214 mi, what is this
distance in miles?
A. 8.0 mi
B. 0.12 mi
C. 3.1 mi [CORRECT]
D. 31 mi
Correct Answer: C
Rationale: 5.0 km × 0.6214 mi/km = 3.1 mi (two significant figures); dividing instead of
multiplying gives 8.0 mi, and dropping a decimal place gives 31 mi.
Q12: Convert 0.750 kg to milligrams.
A. 0.00075 mg
, B. 750 mg
C. 7.50 × 10³ mg
D. 7.50 × 10⁵ mg [CORRECT]
Correct Answer: D
Rationale: 0.750 kg = 750 g, and 750 g × 1000 mg/g = 7.50 × 10⁵ mg; stopping at grams
(750 mg) or missing a factor of 1000 reflects incomplete metric conversion.
Q13: A car travels at 60 mi/hr. Given 1 mi = 1609 m, what is this speed in m/s?
A. 1.6 m/s
B. 26.8 m/s [CORRECT]
C. 96.5 m/s
D. 0.017 m/s
Correct Answer: B
Rationale: (60 × 1609) ÷ 3600 = 26.8 m/s; dividing by 60 only once (giving 96.5 or 1609)
reflects incomplete unit cancellation of hours to seconds.
Q14: A cube measures 2.0 cm on each side. What is its volume, reported correctly?
A. 8 cm³
B. 8.00 cm³
C. 8.0 cm³ [CORRECT]
D. 6.0 cm³
Correct Answer: C
Rationale: V = 2.0³ = 8.0 cm³, and multiplying/dividing requires the fewest significant
figures (2.0 has two), so the answer is 8.0 cm³; adding a cubed side instead of
multiplying gives 6.0.
Q15: A pencil is 30.5 cm long. Using 1 in = 2.54 cm, what is its length in inches?
A. 12.0 in [CORRECT]
B. 77.5 in
C. 1.20 in
D. 0.083 in
Correct Answer: A
Rationale: 30.5 cm ÷ 2.54 cm/in = 12.0 in; multiplying by 2.54 instead of dividing gives
77.5 in, a classic inverted-conversion-factor error.
Q16: The metric prefix "micro" (μ) represents which multiplier?
A. 10⁻³
B. 10⁻⁶ [CORRECT]
C. 10⁶
D. 10⁻⁹
