Solutions and Concentration Quiz. Solutions and concentration are important topics in chemistry that help students understand how substances dissolve, mix, and react in different proportions. A good knowledge of this topic is essential for solving numerical problems and answering examination questions correctly. This quiz is designed to test your understanding of solutions, solubility, molarity, molality, and related concepts in a practical and exam-focused way. Score yourself over 25 with the answers and explanations.
Solutions and Concentration Quiz
1. Which of the following best describes a true solution?
A. A mixture in which solid particles are visible to the naked eye
B. A homogeneous mixture with particle size less than 1 nm
C. A heterogeneous mixture that settles on standing
D. A mixture that can be separated by simple filtration
2. When 5 g of sodium chloride is dissolved in 250 cm³ of water, the solution formed is best described as
A. A suspension because the particles are large
B. A colloid because light is scattered
C. A true solution because the solute is completely dispersed
D. A saturated solution because no more solute can dissolve
3. Which unit is most commonly used to express molar concentration in chemical calculations?
A. mol/kg
B. g/dm³
C. mol/dm³
D. mol/cm³
4. A solution contains 0.50 mol of potassium nitrate in 500 cm³ of water. What is its molarity?
A. 0.25 mol/dm³
B. 0.50 mol/dm³
C. 1.00 mol/dm³
D. 2.00 mol/dm³
5. Which factor has the greatest effect on the solubility of gases in liquids?
A. Temperature only
B. Pressure only
C. Volume of solvent
D. Nature of container
Solutions and Concentration Quiz
6. A saturated solution is best described as a solution that
A. Contains more solute than solvent
B. Cannot dissolve any more solute at a given temperature
C. Has low concentration
D. Is always hot
7. Which of the following will increase the solubility of most solid solutes in water?
A. Decreasing temperature
B. Increasing pressure
C. Increasing temperature
D. Reducing solvent volume
8. What is the molarity of a solution containing 4 g of NaOH in 500 cm³ of water? (NaOH = 40 g/mol)
A. 0.10 mol/dm³
B. 0.20 mol/dm³
C. 0.40 mol/dm³
D. 0.50 mol/dm³
9. A solution that contains less solute than it can dissolve at a given temperature is called
A. Saturated
B. Supersaturated
C. Unsaturated
D. Concentrated
10. Which method is best for preparing a standard solution in the laboratory?
A. Measuring with a beaker
B. Using a measuring cylinder
C. Using a volumetric flask
D. Using a test tube
Solutions and Concentration Quiz
11. What is meant by the term solubility?
A. Amount of solvent in a solution
B. Maximum amount of solute that dissolves at a given temperature
C. Rate of dissolution
D. Volume of solution formed
12. A solution has a concentration of 2 mol/dm³. How many moles are present in 250 cm³ of the solution?
A. 0.25 mol
B. 0.50 mol
C. 1.00 mol
D. 2.00 mol
13. Which of the following is most likely to form a colloidal solution?
A. Sugar in water
B. Salt in water
C. Milk in water
D. Ethanol in water
14. Molality is defined as the number of moles of solute per
A. dm³ of solution
B. litre of solvent
C. kilogram of solvent
D. gram of solution
15. Which process can be used to separate a solute from its solution?
A. Filtration
B. Distillation
C. Crystallization
D. Sedimentation
16. The concentration of a solution decreases when
A. More solute is added
B. More solvent is added
C. Temperature is increased
D. Pressure is increased
17. Which of the following will produce a supersaturated solution?
A. Adding solute to cold water
B. Cooling a hot saturated solution slowly
C. Heating an unsaturated solution
D. Shaking a saturated solution
18. A 1 dm³ solution contains 20 g of calcium carbonate. What is its concentration in g/dm³?
A. 5 g/dm³
B. 10 g/dm³
C. 20 g/dm³
D. 40 g/dm³
19. Which of the following factors does NOT affect solubility?
A. Temperature
B. Pressure
C. Nature of solute
D. Colour of solute
20. A solution prepared by dissolving 5 mol of solute in 2 dm³ of water has a molarity of
A. 1.5 mol/dm³
B. 2.0 mol/dm³
C. 2.5 mol/dm³
D. 3.0 mol/dm³
Solutions and Concentration Quiz
21. Which type of solution conducts electricity best?
A. Sugar solution
B. Salt solution
C. Alcohol solution
D. Starch solution
22. What happens when a saturated solution is heated?
A. It becomes supersaturated
B. It becomes unsaturated
C. It becomes concentrated
D. It becomes dilute
23. Which of the following is an example of a dilute solution?
A. Large solute in small solvent
B. Small solute in large solvent
C. Equal solute and solvent
D. No solvent
24. The unit g/dm³ expresses concentration in terms of
A. Moles and volume
B. Mass and volume
C. Mass and mass
D. Moles and mass
25. Which laboratory apparatus is most suitable for accurate dilution of a solution?
A. Beaker
B. Conical flask
C. Volumetric flask
D. Test tube
Solutions and Concentration Quiz Answers and Explanations
1. Answer: B
Explanation: True solutions are homogeneous and have very small particles.
2. Answer: C
Explanation: Sodium chloride dissolves completely to form a true solution.
3. Answer: C
Explanation: Molarity is measured in mol/dm³.
4. Answer: C
Explanation: 0.50 mol ÷ 0.5 dm³ = 1.00 mol/dm³.
5. Answer: B
Explanation: Gas solubility depends mainly on pressure.
6. Answer: B
Explanation: A saturated solution cannot dissolve more solute.
7. Answer: C
Explanation: Higher temperature increases solubility of most solids.
8. Answer: B
Explanation: Moles = 4/40 = 0.1; Volume = 0.5 dm³; M = 0.2.
9. Answer: C
Explanation: Unsaturated solutions can still dissolve more solute.
10. Answer: C
Explanation: Volumetric flasks give accurate volume.
11. Answer: B
Explanation: Solubility is the maximum amount that dissolves.
12. Answer: B
Explanation: 2 × 0.25 = 0.50 mol.
13. Answer: C
Explanation: Milk forms a colloid.
14. Answer: C
Explanation: Molality is based on kilogram of solvent.
15. Answer: C
Explanation: Crystallization separates solid solute.
16. Answer: B
Explanation: Adding solvent reduces concentration.
17. Answer: B
Explanation: Slow cooling forms supersaturated solutions.
18. Answer: C
Explanation: 20 g in 1 dm³ = 20 g/dm³.
19. Answer: D
Explanation: Colour does not affect solubility.
20. Answer: C
Explanation: 5 ÷ 2 = 2.5 mol/dm³.
21. Answer: B
Explanation: Salt solutions contain ions.
22. Answer: B
Explanation: Heating increases solubility.
23. Answer: B
Explanation: Dilute solutions have little solute.
24. Answer: B
Explanation: g/dm³ means mass per volume.
25. Answer: C
Explanation: Volumetric flasks ensure accurate dilution.
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