CHEM 103 General Chemistry I Modules 1-
6 Comprehensive Exam 2026/2027 | 50
Verified Questions & Answers | Portage
Learning
Module 1: Matter, Measurements, and Problem Solving
1. Which of the following is a homogeneous mixture?
• A) Sand and water
• B) Saltwater
• C) Oil and vinegar
• D) Granite rock
Correct Answer: B) Saltwater
Rationale: A homogeneous mixture has uniform composition throughout.
Saltwater is a solution where salt is completely dissolved in water, appearing as a
single phase. Sand and water (A), oil and vinegar (C), and granite (D) are
heterogeneous mixtures with visibly distinct components.
2. How many significant figures are in the number 0.004560?
• A) 3
• B) 4
• C) 6
• D) 7
Correct Answer: B) 4
, Rationale: Leading zeros are not significant. The significant figures are 4, 5, 6,
and the trailing zero after the decimal (0.004560). The digits 4, 5, 6, and the final 0
= 4 significant figures.
3. Express 0.0000456 in scientific notation.
• A) 4.56 × 10⁻⁵
• B) 4.56 × 10⁻⁴
• C) 45.6 × 10⁻⁶
• D) 0.456 × 10⁻⁴
Correct Answer: A) 4.56 × 10⁻⁵
Rationale: Move the decimal point 5 places to the right to get 4.56. Since we
moved right, the exponent is negative: 4.56 × 10⁻⁵.
4. Which of the following is a chemical property?
• A) Melting point
• B) Density
• C) Flammability
• D) Solubility
Correct Answer: C) Flammability
Rationale: Chemical properties describe how a substance reacts or changes
into a new substance. Flammability is the ability to burn, which is a chemical
change. Melting point (A), density (B), and solubility (D) are physical properties.
5. Convert 25.0°C to Kelvin.
, • A) 298.15 K
• B) 248.15 K
• C) 273.15 K
• D) 25.0 K
Correct Answer: A) 298.15 K
Rationale: K = °C + 273.15 = 25.0 + 273.15 = 298.15 K.
6. Which state of matter has a definite volume but no definite shape?
• A) Solid
• B) Liquid
• C) Gas
• D) Plasma
Correct Answer: B) Liquid
Rationale: Liquids have definite volume (particles are close together) but no
definite shape (particles can flow). Solids (A) have both definite shape and
volume. Gases (C) have neither. Plasma (D) has neither.
7. What is the density of an object with a mass of 45.0 g and a volume of 15.0 mL?
• A) 0.333 g/mL
• B) 3.00 g/mL
• C) 675 g/mL
• D) 30.0 g/mL
Correct Answer: B) 3.00 g/mL
, Rationale: Density = mass/volume = 45.0 g / 15.0 mL = 3.00 g/mL.
8. How many centimeters are in 2.50 meters?
• A) 0.025 cm
• B) 25.0 cm
• C) 250 cm
• D) 2500 cm
Correct Answer: C) 250 cm
Rationale: 1 m = 100 cm, so 2.50 m × 100 cm/m = 250 cm.
9. Which of the following represents a physical change?
• A) Rusting of iron
• B) Burning of wood
• C) Dissolving sugar in water
• D) Baking a cake
Correct Answer: C) Dissolving sugar in water
Rationale: A physical change does not alter the chemical composition.
Dissolving sugar in water is a physical change because sugar can be recovered by
evaporation. Rusting (A), burning (B), and baking (D) are chemical changes.
10. The number 6.022 × 10²³ is known as:
• A) Planck's constant
• B) Avogadro's number
6 Comprehensive Exam 2026/2027 | 50
Verified Questions & Answers | Portage
Learning
Module 1: Matter, Measurements, and Problem Solving
1. Which of the following is a homogeneous mixture?
• A) Sand and water
• B) Saltwater
• C) Oil and vinegar
• D) Granite rock
Correct Answer: B) Saltwater
Rationale: A homogeneous mixture has uniform composition throughout.
Saltwater is a solution where salt is completely dissolved in water, appearing as a
single phase. Sand and water (A), oil and vinegar (C), and granite (D) are
heterogeneous mixtures with visibly distinct components.
2. How many significant figures are in the number 0.004560?
• A) 3
• B) 4
• C) 6
• D) 7
Correct Answer: B) 4
, Rationale: Leading zeros are not significant. The significant figures are 4, 5, 6,
and the trailing zero after the decimal (0.004560). The digits 4, 5, 6, and the final 0
= 4 significant figures.
3. Express 0.0000456 in scientific notation.
• A) 4.56 × 10⁻⁵
• B) 4.56 × 10⁻⁴
• C) 45.6 × 10⁻⁶
• D) 0.456 × 10⁻⁴
Correct Answer: A) 4.56 × 10⁻⁵
Rationale: Move the decimal point 5 places to the right to get 4.56. Since we
moved right, the exponent is negative: 4.56 × 10⁻⁵.
4. Which of the following is a chemical property?
• A) Melting point
• B) Density
• C) Flammability
• D) Solubility
Correct Answer: C) Flammability
Rationale: Chemical properties describe how a substance reacts or changes
into a new substance. Flammability is the ability to burn, which is a chemical
change. Melting point (A), density (B), and solubility (D) are physical properties.
5. Convert 25.0°C to Kelvin.
, • A) 298.15 K
• B) 248.15 K
• C) 273.15 K
• D) 25.0 K
Correct Answer: A) 298.15 K
Rationale: K = °C + 273.15 = 25.0 + 273.15 = 298.15 K.
6. Which state of matter has a definite volume but no definite shape?
• A) Solid
• B) Liquid
• C) Gas
• D) Plasma
Correct Answer: B) Liquid
Rationale: Liquids have definite volume (particles are close together) but no
definite shape (particles can flow). Solids (A) have both definite shape and
volume. Gases (C) have neither. Plasma (D) has neither.
7. What is the density of an object with a mass of 45.0 g and a volume of 15.0 mL?
• A) 0.333 g/mL
• B) 3.00 g/mL
• C) 675 g/mL
• D) 30.0 g/mL
Correct Answer: B) 3.00 g/mL
, Rationale: Density = mass/volume = 45.0 g / 15.0 mL = 3.00 g/mL.
8. How many centimeters are in 2.50 meters?
• A) 0.025 cm
• B) 25.0 cm
• C) 250 cm
• D) 2500 cm
Correct Answer: C) 250 cm
Rationale: 1 m = 100 cm, so 2.50 m × 100 cm/m = 250 cm.
9. Which of the following represents a physical change?
• A) Rusting of iron
• B) Burning of wood
• C) Dissolving sugar in water
• D) Baking a cake
Correct Answer: C) Dissolving sugar in water
Rationale: A physical change does not alter the chemical composition.
Dissolving sugar in water is a physical change because sugar can be recovered by
evaporation. Rusting (A), burning (B), and baking (D) are chemical changes.
10. The number 6.022 × 10²³ is known as:
• A) Planck's constant
• B) Avogadro's number
