Chemistry 121: Solutions, Concentration, Acids, and Bases 2026/2027
UPDATE
1. Which component of a solution is present in the greatest amount?
A. Solute
B. Solvent
C. Electrolyte
D. Precipitate
Answer: B
Rationale: The solvent is the substance that does the dissolving and is present in the larger
quantity in a solution.
2. Which of the following describes a saturated solution?
A. A solution that can dissolve more solute.
B. A solution where the solute has precipitated out.
C. A solution that is very dilute.
D. A solution containing the maximum amount of dissolved solute at a given temperature.
Answer: D
Rationale: A saturated solution contains the maximum amount of solute that can be
dissolved in the solvent at a specific temperature and pressure.
,3. What happens to the solubility of most solid solutes as the temperature of
the solvent increases?
A. It increases.
B. It remains the same.
C. It decreases.
D. It fluctuates randomly.
Answer: A
Rationale: For most solid solutes, solubility in a liquid solvent increases as the
temperature increases.
4. According to the ‘like dissolves like’ rule, which of the following will most
likely dissolve in water?
A. Sodium chloride (ionic)
B. Hexane (nonpolar)
C. Oil
D. Iodine (nonpolar)
Answer: A
Rationale: Water is a polar solvent and dissolves polar or ionic substances like sodium
chloride.
5. What is the molarity of a solution containing 0.5 moles of solute in 2.0 liters
of solution?
A. 1.0 M
B. 0.25 M
C. 4.0 M
D. 0.5 M
Answer: B
Rationale: Molarity (M) = moles of solute / liters of solution. 0.5 moles / 2.0 L = 0.25 M.
, 6. In a dilution, which of the following remains constant?
A. Volume of the solution
B. Molarity of the solution
C. Density of the solution
D. Number of moles of solute
Answer: D
Rationale: Dilution involves adding solvent, so the total volume and molarity change, but
the total moles of solute stay the same.
7. What is the mass percent (w/w%) of a solution prepared by dissolving 10g of
NaCl in 90g of water?
A. 10.0%
B. 11.1%
C. 9.0%
D. 1.0%
Answer: A
Rationale: Mass percent = (mass of solute / total mass of solution) x 100. (10 / (10+90)) x
100 = 10%.
8. Which of the following is an Arrhenius acid?
A. NaOH
B. NH3
C. HCl
D. NaCl
Answer: C
Rationale: An Arrhenius acid is a substance that increases the concentration of hydrogen
ions (H+) when dissolved in water.
UPDATE
1. Which component of a solution is present in the greatest amount?
A. Solute
B. Solvent
C. Electrolyte
D. Precipitate
Answer: B
Rationale: The solvent is the substance that does the dissolving and is present in the larger
quantity in a solution.
2. Which of the following describes a saturated solution?
A. A solution that can dissolve more solute.
B. A solution where the solute has precipitated out.
C. A solution that is very dilute.
D. A solution containing the maximum amount of dissolved solute at a given temperature.
Answer: D
Rationale: A saturated solution contains the maximum amount of solute that can be
dissolved in the solvent at a specific temperature and pressure.
,3. What happens to the solubility of most solid solutes as the temperature of
the solvent increases?
A. It increases.
B. It remains the same.
C. It decreases.
D. It fluctuates randomly.
Answer: A
Rationale: For most solid solutes, solubility in a liquid solvent increases as the
temperature increases.
4. According to the ‘like dissolves like’ rule, which of the following will most
likely dissolve in water?
A. Sodium chloride (ionic)
B. Hexane (nonpolar)
C. Oil
D. Iodine (nonpolar)
Answer: A
Rationale: Water is a polar solvent and dissolves polar or ionic substances like sodium
chloride.
5. What is the molarity of a solution containing 0.5 moles of solute in 2.0 liters
of solution?
A. 1.0 M
B. 0.25 M
C. 4.0 M
D. 0.5 M
Answer: B
Rationale: Molarity (M) = moles of solute / liters of solution. 0.5 moles / 2.0 L = 0.25 M.
, 6. In a dilution, which of the following remains constant?
A. Volume of the solution
B. Molarity of the solution
C. Density of the solution
D. Number of moles of solute
Answer: D
Rationale: Dilution involves adding solvent, so the total volume and molarity change, but
the total moles of solute stay the same.
7. What is the mass percent (w/w%) of a solution prepared by dissolving 10g of
NaCl in 90g of water?
A. 10.0%
B. 11.1%
C. 9.0%
D. 1.0%
Answer: A
Rationale: Mass percent = (mass of solute / total mass of solution) x 100. (10 / (10+90)) x
100 = 10%.
8. Which of the following is an Arrhenius acid?
A. NaOH
B. NH3
C. HCl
D. NaCl
Answer: C
Rationale: An Arrhenius acid is a substance that increases the concentration of hydrogen
ions (H+) when dissolved in water.
