,CHEM 103 Final Exam | Practice Q&A | 2026/2027 | Chemistry |
Portage Learning | 100% PASS
1. What is the definition of matter?
A) Anything that has mass and takes up space
B) The energy released during a chemical reaction
C) A substance that cannot be broken down chemically
D) The ability to do work
Correct Answer: Anything that has mass and takes up space
Rationale: Matter is defined as anything that has mass and occupies volume
(takes up space). Energy is the ability to do work, and elements are
substances that cannot be broken down chemically.
2. Convert 0.000453 to scientific notation.
A) 4.53 × 10⁻⁴
B) 45.3 × 10⁻⁵
C) 4.53 × 10⁴
D) 0.453 × 10⁻³
Correct Answer: 4.53 × 10⁻⁴
Rationale: To convert to scientific notation, move the decimal point so there
is one non-zero digit to the left. For 0.000453, the decimal moves 4 places to
the right, giving 4.53 × 10⁻⁴. The exponent is negative because the original
number is less than 1.
3. How many significant figures are in the number 0.03040?
A) 3
,B) 4
C) 5
D) 6
Correct Answer: 4
Rationale: Leading zeros are not significant. The zeros between non-zero
digits are significant, and trailing zeros after a decimal are significant.
0.03040 has 4 significant figures (3, 0, 4, and the trailing 0).
4. Perform the following calculation and report the answer with the correct
number of significant figures: 12.34 × 5.6
A) 69.104
B) 69.10
C) 69
D) 69.1
Correct Answer: 69
Rationale: For multiplication, the result should contain the same number of
significant figures as the measurement with the least number of significant
figures. 5.6 has 2 significant figures, so the answer should have 2 significant
figures: 69.
5. Convert 25°C to Kelvin.
A) 248 K
B) 273 K
C) 298 K
D) 300 K
, Correct Answer: 298 K
Rationale: To convert from Celsius to Kelvin, add 273.15 to the Celsius
temperature: K = °C + 273.15. 25 + 273.15 = 298.15 K ≈ 298 K.
6. Convert 68°F to Celsius.
A) 20°C
B) 25°C
C) 30°C
D) 35°C
Correct Answer: 20°C
Rationale: To convert Fahrenheit to Celsius: °C = (°F - 32) ÷ 1.8. (68 - 32) ÷
1.8 = 36 ÷ 1.8 = 20°C.
7. What is the density of a substance with a mass of 54.0 g and a volume of
20.0 mL?
A) 0.370 g/mL
B) 2.70 g/mL
C) 3.00 g/mL
D) 1080 g/mL
Correct Answer: 2.70 g/mL
Rationale: Density = mass / volume = 54.0 g / 20.0 mL = 2.70 g/mL. This is
the known density of aluminum.
Portage Learning | 100% PASS
1. What is the definition of matter?
A) Anything that has mass and takes up space
B) The energy released during a chemical reaction
C) A substance that cannot be broken down chemically
D) The ability to do work
Correct Answer: Anything that has mass and takes up space
Rationale: Matter is defined as anything that has mass and occupies volume
(takes up space). Energy is the ability to do work, and elements are
substances that cannot be broken down chemically.
2. Convert 0.000453 to scientific notation.
A) 4.53 × 10⁻⁴
B) 45.3 × 10⁻⁵
C) 4.53 × 10⁴
D) 0.453 × 10⁻³
Correct Answer: 4.53 × 10⁻⁴
Rationale: To convert to scientific notation, move the decimal point so there
is one non-zero digit to the left. For 0.000453, the decimal moves 4 places to
the right, giving 4.53 × 10⁻⁴. The exponent is negative because the original
number is less than 1.
3. How many significant figures are in the number 0.03040?
A) 3
,B) 4
C) 5
D) 6
Correct Answer: 4
Rationale: Leading zeros are not significant. The zeros between non-zero
digits are significant, and trailing zeros after a decimal are significant.
0.03040 has 4 significant figures (3, 0, 4, and the trailing 0).
4. Perform the following calculation and report the answer with the correct
number of significant figures: 12.34 × 5.6
A) 69.104
B) 69.10
C) 69
D) 69.1
Correct Answer: 69
Rationale: For multiplication, the result should contain the same number of
significant figures as the measurement with the least number of significant
figures. 5.6 has 2 significant figures, so the answer should have 2 significant
figures: 69.
5. Convert 25°C to Kelvin.
A) 248 K
B) 273 K
C) 298 K
D) 300 K
, Correct Answer: 298 K
Rationale: To convert from Celsius to Kelvin, add 273.15 to the Celsius
temperature: K = °C + 273.15. 25 + 273.15 = 298.15 K ≈ 298 K.
6. Convert 68°F to Celsius.
A) 20°C
B) 25°C
C) 30°C
D) 35°C
Correct Answer: 20°C
Rationale: To convert Fahrenheit to Celsius: °C = (°F - 32) ÷ 1.8. (68 - 32) ÷
1.8 = 36 ÷ 1.8 = 20°C.
7. What is the density of a substance with a mass of 54.0 g and a volume of
20.0 mL?
A) 0.370 g/mL
B) 2.70 g/mL
C) 3.00 g/mL
D) 1080 g/mL
Correct Answer: 2.70 g/mL
Rationale: Density = mass / volume = 54.0 g / 20.0 mL = 2.70 g/mL. This is
the known density of aluminum.
