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Comprehensive Chemistry: Solutions, Electrolytes & Redox Reactions Study Guide &
Practice Questions 2026–2027
Study Guide Note: This practice exam covers the core topics of solutions, electrolytes, and
oxidation-reduction (redox) reactions, aligned with the 2026–2027 general and preparatory
chemistry curriculum. Each question includes the correct answer and a detailed rationale
grounded in fundamental chemical principles. Key concepts include solubility rules,
colligative properties, molarity calculations, Arrhenius and Brønsted-Lowry acid-base theory,
oxidation states, and electrochemical cells.
Section 1: Solutions & Solubility (Questions 1–20)
1. Which of the following best defines a solution?
A. A heterogeneous mixture of two or more substances
B. A homogeneous mixture of two or more substances uniformly distributed
C. A compound formed by chemical bonding
D. A suspension of particles that settle over time
Answer: B. A solution is a homogeneous mixture in which the solute is uniformly distributed
throughout the solvent. The particles are too small to see and do not settle.
2. In a solution of salt water, the salt is the:
A. Solvent
B. Solute
C. Solution
D. Precipitate
Answer: B. The solute is the substance that is dissolved (salt). The solvent is the substance
that does the dissolving (water). Together they form a solution.
3. What is the term for a solution that contains the maximum amount of solute that can
be dissolved at a given temperature?
A. Unsaturated
B. Saturated
C. Supersaturated
D. Dilute
Answer: B. A saturated solution contains the maximum amount of solute that can dissolve at
a given temperature. An unsaturated solution can dissolve more solute.
4. A solution that contains more dissolved solute than would normally be possible at a
given temperature is called:
A. Unsaturated
B. Saturated
,2
C. Supersaturated
D. Concentrated
Answer: C. A supersaturated solution contains more dissolved solute than would normally
be possible at that temperature, often achieved by cooling a saturated solution slowly.
5. According to the solubility rules, which of the following compounds is SOLUBLE in
water?
A. AgCl
B. BaSO₄
C. NaCl
D. PbI₂
Answer: C. Sodium chloride (NaCl) is soluble. Salts of sodium (Na⁺), potassium (K⁺), and
ammonium (NH₄⁺) are always soluble. AgCl, BaSO₄, and PbI₂ are insoluble exceptions.
6. Which of the following compounds is INSOLUBLE in water?
A. KNO₃
B. NH₄Cl
C. CaCO₃
D. Na₂SO₄
Answer: C. Calcium carbonate (CaCO₃) is insoluble. Most carbonates (CO₃²⁻) are insoluble
except those of Group 1 elements and ammonium.
7. Which factor increases the solubility of a gas in a liquid?
A. Increasing temperature
B. Decreasing pressure
C. Increasing pressure
D. Adding more solvent
Answer: C. According to Henry's Law, gas solubility increases with increasing pressure. Gas
solubility decreases with increasing temperature.
8. Which factor generally increases the solubility of a solid in a liquid?
A. Decreasing temperature
B. Increasing temperature
C. Decreasing pressure
D. Adding a catalyst
Answer: B. For most solids, solubility increases with increasing temperature. Pressure
changes have negligible effect on solids and liquids.
9. What is the molarity of a solution containing 0.50 moles of NaCl in 2.0 liters of solution?
, 3
A. 0.25 M
B. 1.0 M
C. 2.0 M
D. 0.50 M
Answer: A. Molarity (M) = moles of solute ÷ liters of solution = 0.50 mol ÷ 2.0 L = 0.25 M.
10. How many grams of NaOH (molar mass = 40 g/mol) are needed to prepare 500 mL of a
0.20 M solution?
A. 2.0 g
B. 4.0 g
C. 8.0 g
D. 20.0 g
Answer: B. Moles = M × L = 0.20 × 0.500 = 0.100 mol. Mass = 0.100 × 40 = 4.0 g.
11. What is the molality of a solution containing 2.0 moles of solute in 1.0 kg of solvent?
A. 0.5 m
B. 1.0 m
C. 2.0 m
D. 4.0 m
Answer: C. Molality (m) = moles of solute ÷ kilograms of solvent = 2.0 mol ÷ 1.0 kg = 2.0 m.
12. Which concentration unit is temperature-independent?
A. Molarity
B. Molality
C. Percent by volume
D. Normality
Answer: B. Molality is temperature-independent because it is based on mass (kg) rather
than volume, which changes with temperature.
13. What is the effect of a nonvolatile solute on the boiling point of a solvent?
A. Boiling point decreases
B. Boiling point increases
C. Boiling point remains the same
D. Boiling point becomes unpredictable
Answer: B. Boiling point elevation is a colligative property. Adding a nonvolatile solute raises
the boiling point of the solvent.
14. What is the effect of a nonvolatile solute on the freezing point of a solvent?
Comprehensive Chemistry: Solutions, Electrolytes & Redox Reactions Study Guide &
Practice Questions 2026–2027
Study Guide Note: This practice exam covers the core topics of solutions, electrolytes, and
oxidation-reduction (redox) reactions, aligned with the 2026–2027 general and preparatory
chemistry curriculum. Each question includes the correct answer and a detailed rationale
grounded in fundamental chemical principles. Key concepts include solubility rules,
colligative properties, molarity calculations, Arrhenius and Brønsted-Lowry acid-base theory,
oxidation states, and electrochemical cells.
Section 1: Solutions & Solubility (Questions 1–20)
1. Which of the following best defines a solution?
A. A heterogeneous mixture of two or more substances
B. A homogeneous mixture of two or more substances uniformly distributed
C. A compound formed by chemical bonding
D. A suspension of particles that settle over time
Answer: B. A solution is a homogeneous mixture in which the solute is uniformly distributed
throughout the solvent. The particles are too small to see and do not settle.
2. In a solution of salt water, the salt is the:
A. Solvent
B. Solute
C. Solution
D. Precipitate
Answer: B. The solute is the substance that is dissolved (salt). The solvent is the substance
that does the dissolving (water). Together they form a solution.
3. What is the term for a solution that contains the maximum amount of solute that can
be dissolved at a given temperature?
A. Unsaturated
B. Saturated
C. Supersaturated
D. Dilute
Answer: B. A saturated solution contains the maximum amount of solute that can dissolve at
a given temperature. An unsaturated solution can dissolve more solute.
4. A solution that contains more dissolved solute than would normally be possible at a
given temperature is called:
A. Unsaturated
B. Saturated
,2
C. Supersaturated
D. Concentrated
Answer: C. A supersaturated solution contains more dissolved solute than would normally
be possible at that temperature, often achieved by cooling a saturated solution slowly.
5. According to the solubility rules, which of the following compounds is SOLUBLE in
water?
A. AgCl
B. BaSO₄
C. NaCl
D. PbI₂
Answer: C. Sodium chloride (NaCl) is soluble. Salts of sodium (Na⁺), potassium (K⁺), and
ammonium (NH₄⁺) are always soluble. AgCl, BaSO₄, and PbI₂ are insoluble exceptions.
6. Which of the following compounds is INSOLUBLE in water?
A. KNO₃
B. NH₄Cl
C. CaCO₃
D. Na₂SO₄
Answer: C. Calcium carbonate (CaCO₃) is insoluble. Most carbonates (CO₃²⁻) are insoluble
except those of Group 1 elements and ammonium.
7. Which factor increases the solubility of a gas in a liquid?
A. Increasing temperature
B. Decreasing pressure
C. Increasing pressure
D. Adding more solvent
Answer: C. According to Henry's Law, gas solubility increases with increasing pressure. Gas
solubility decreases with increasing temperature.
8. Which factor generally increases the solubility of a solid in a liquid?
A. Decreasing temperature
B. Increasing temperature
C. Decreasing pressure
D. Adding a catalyst
Answer: B. For most solids, solubility increases with increasing temperature. Pressure
changes have negligible effect on solids and liquids.
9. What is the molarity of a solution containing 0.50 moles of NaCl in 2.0 liters of solution?
, 3
A. 0.25 M
B. 1.0 M
C. 2.0 M
D. 0.50 M
Answer: A. Molarity (M) = moles of solute ÷ liters of solution = 0.50 mol ÷ 2.0 L = 0.25 M.
10. How many grams of NaOH (molar mass = 40 g/mol) are needed to prepare 500 mL of a
0.20 M solution?
A. 2.0 g
B. 4.0 g
C. 8.0 g
D. 20.0 g
Answer: B. Moles = M × L = 0.20 × 0.500 = 0.100 mol. Mass = 0.100 × 40 = 4.0 g.
11. What is the molality of a solution containing 2.0 moles of solute in 1.0 kg of solvent?
A. 0.5 m
B. 1.0 m
C. 2.0 m
D. 4.0 m
Answer: C. Molality (m) = moles of solute ÷ kilograms of solvent = 2.0 mol ÷ 1.0 kg = 2.0 m.
12. Which concentration unit is temperature-independent?
A. Molarity
B. Molality
C. Percent by volume
D. Normality
Answer: B. Molality is temperature-independent because it is based on mass (kg) rather
than volume, which changes with temperature.
13. What is the effect of a nonvolatile solute on the boiling point of a solvent?
A. Boiling point decreases
B. Boiling point increases
C. Boiling point remains the same
D. Boiling point becomes unpredictable
Answer: B. Boiling point elevation is a colligative property. Adding a nonvolatile solute raises
the boiling point of the solvent.
14. What is the effect of a nonvolatile solute on the freezing point of a solvent?
