Chapter 9 of Class 8 Science from NCERT book is The Amazing World of Solutes, Solvents, and Solutions. This chapter explains solutions, solutes, solvents, and how much of a substance can dissolve in another. It also introduces density, shows how to measure mass and volume. It further has details on why some things float while others sink.
This set of MCQs and match-the-following questions is going to help you revise the different topics from Chapter 9. Concepts like solutions, solute, solvent, concentration, saturated and unsaturated solutions, solubility, effect of temperature on solubility etc. are dealt with in detail. Solving these questions will help you in making your understanding sharper and revision faster.
Please check MCQ for other chapters with other details here Class 8 Science MCQ Questions and Answers.
Class 8 Science Chapter 9 MCQ The Amazing World of Solutes, Solvents, and Solutions Online Test Questions and Answers
Question 1. A solution is best described as:
a) Any mixture of two solids
b) A uniform mixture formed when substances mix evenly
c) A mixture in which the components can always be seen separately
d) Only a mixture of gases
Answer:
b) A uniform mixture formed when substances mix evenly
Question 2. When sugar and salt are mixed with water to prepare ORS, every sip tastes the same because the mixture is:
a) Non-uniform
b) Saturated
c) Uniform
d) Colloidal
Answer:
c) Uniform
Question 3. Which of the following forms a non-uniform mixture with water?
a) Sugar
b) Salt
c) Chalk powder
d) Glucose
Answer:
c) Chalk powder
Question 4. In a solution formed by mixing a solid with a liquid, the solid component is called the:
a) Solvent
b) Solution
c) Solute
d) Suspension
Answer:
c) Solute
Question 5. In a solution formed by mixing a solid with a liquid, the liquid component is called the:
a) Solute
b) Solvent
c) Concentrate
d) Residue
Answer:
b) Solvent
Question 6. When two liquids are mixed to form a solution, the substance present in smaller amount is generally called the:
a) Solvent
b) Solute
c) Meniscus
d) Deposit
Answer:
b) Solute
Question 7. Air is called a gaseous solution because:
a) It contains only oxygen
b) Its gases are evenly mixed
c) It is a non-uniform mixture
d) Nitrogen is absent in it
Answer:
b) Its gases are evenly mixed
Question 8. In air, nitrogen is considered the solvent mainly because it is present in:
a) Smallest amount
b) Largest amount
c) Equal amount with oxygen
d) Fixed ratio with argon
Answer:
b) Largest amount
Question 9. In sugar syrup for gulab jamun, water is still called the solvent even though sugar is in large amount because:
a) Water is a liquid and sugar is a solid
b) Sugar is heavier than water
c) Water always acts as a solute
d) Sugar cannot dissolve in water
Answer:
a) Water is a liquid and sugar is a solid
Question 10. A solution in which more solute can still dissolve at a given temperature is called:
a) Saturated solution
b) Unsaturated solution
c) Concentrated solution
d) Dilute solvent
Answer:
b) Unsaturated solution
Question 11. When added solute stops dissolving and begins to settle at the bottom, the solution becomes:
a) Dilute
b) Unsaturated
c) Saturated
d) Non-uniform only
Answer:
c) Saturated
Question 12. The amount of solute present in a fixed quantity of solution or solvent is called its:
a) Mass
b) Volume
c) Concentration
d) Density
Answer:
c) Concentration
Question 13. Which statement correctly compares a dilute solution and a concentrated solution?
a) A dilute solution always contains no solute
b) A concentrated solution always contains undissolved solute
c) A concentrated solution has more solute than a dilute one in the same amount of solvent or solution
d) Both terms mean the same thing
Answer:
c) A concentrated solution has more solute than a dilute one in the same amount of solvent or solution
Question 14. Which of the following is more concentrated?
a) 2 spoons of salt in 100 mL water
b) 4 spoons of salt in 50 mL water
c) Both are equal
d) Cannot be compared at all
Answer:
b) 4 spoons of salt in 50 mL water
Question 15. Solubility is defined as the:
a) Total amount of solvent in a solution
b) Maximum amount of solute that dissolves in a fixed quantity of solvent at a particular temperature
c) Amount of solution prepared in one beaker
d) Rate at which a solute dissolves
Answer:
b) Maximum amount of solute that dissolves in a fixed quantity of solvent at a particular temperature
Question 16. For most solid substances, solubility in a liquid generally:
a) Decreases with rise in temperature
b) Increases with rise in temperature
c) Remains exactly unchanged
d) Becomes zero on heating
Answer:
b) Increases with rise in temperature
Question 17. A saturated solution at one temperature behaves as an unsaturated solution when the temperature is:
a) Decreased sharply
b) Increased
c) Kept unchanged
d) Made zero
Answer:
b) Increased
Question 18. Oxygen dissolved in water is important because it:
a) Makes water sweeter
b) Sustains aquatic life
c) Increases the colour of water
d) Makes water denser than all liquids
Answer:
b) Sustains aquatic life
Question 19. The solubility of gases in liquids generally:
a) Increases with temperature
b) Decreases with temperature
c) Remains unaffected by temperature
d) Depends only on colour of liquid
Answer:
b) Decreases with temperature
Question 20. More oxygen dissolves in cold water than in warm water because the solubility of gases:
a) Increases with increase in temperature
b) Decreases with increase in temperature
c) Is maximum at all temperatures
d) Depends only on pressure, not temperature
Answer:
b) Decreases with increase in temperature
Question 21. Density is defined as:
a) Volume per unit mass
b) Mass per unit volume
c) Weight per unit length
d) Pressure per unit area
Answer:
b) Mass per unit volume
Question 22. The density of a substance is independent of its:
a) Temperature
b) Pressure
c) Shape or size
d) State of matter
Answer:
c) Shape or size
Question 23. The SI unit of density is:
a) g/mL
b) g/cm3
c) kg/m3
d) kg/L
Answer:
c) kg/m3
Question 24. If 1 mL of water has a mass close to 1 g at room temperature, then 100 mL of water will have a mass of approximately:
a) 10 g
b) 50 g
c) 100 g
d) 1000 g
Answer:
c) 100 g
Question 25. If an aluminium block has a density of 2.7 g/cm3, its relative density with respect to water is:
a) 0.27
b) 1.0
c) 2.7
d) 27
Answer:
c) 2.7
Question 26. Relative density is a number without units because it is the ratio of:
a) Mass to volume
b) Density of a substance to density of water
c) Weight to mass
d) Pressure to force
Answer:
b) Density of a substance to density of water
Question 27. The instrument used in the chapter to measure mass is a:
a) Spring balance
b) Measuring cylinder
c) Digital weighing balance
d) Thermometer
Answer:
c) Digital weighing balance
Question 28. Before measuring mass on a digital balance, the reading should first be brought to zero using the:
a) Pointer
b) Hook
c) Tare or reset button
d) Meniscus mark
Answer:
c) Tare or reset button
Question 29. The common laboratory apparatus used to measure the volume of liquids is a:
a) Beaker
b) Measuring cylinder
c) Watch glass
d) Balance
Answer:
b) Measuring cylinder
Question 30. In a 100 mL measuring cylinder having 10 equal divisions between 10 mL and 20 mL, one small division represents:
a) 0.1 mL
b) 1 mL
c) 2 mL
d) 10 mL
Answer:
b) 1 mL
Question 31. For water and other colourless liquids, the reading in a measuring cylinder should be taken at the:
a) Top of the meniscus
b) Bottom of the meniscus
c) Middle of the cylinder
d) Highest mark nearby
Answer:
b) Bottom of the meniscus
Question 32. The volume of an irregular solid like a stone can be found by:
a) Measuring length, breadth, and height
b) Using only a thermometer
c) Water displacement method
d) Weighing it twice
Answer:
c) Water displacement method
Question 33. If the initial water level in a measuring cylinder is 50 mL and it rises to 55 mL after a stone is immersed, the volume of the stone is:
a) 55 cm3
b) 50 cm3
c) 5 cm3
d) 105 cm3
Answer:
c) 5 cm3
Question 34. Generally, the density of a substance decreases on heating because:
a) Its mass increases and volume decreases
b) Its particles move farther apart, increasing volume
c) Pressure becomes zero
d) It always turns into gas
Answer:
b) Its particles move farther apart, increasing volume
Question 35. Pressure has the greatest effect on the density of:
a) Solids
b) Liquids
c) Gases
d) Metals only
Answer:
c) Gases
Question 36 – Match the Following
| Column A | Column B |
|---|---|
| 1. Solute | A. Liquid present in larger amount in a solution |
| 2. Solvent | B. Maximum amount of solute dissolvable at a given temperature |
| 3. Saturated solution | C. Substance that gets dissolved |
| 4. Unsaturated solution | D. Solution in which more solute can still dissolve |
| 5. Solubility | E. Solution in which no more solute dissolves at that temperature |
Answer:
| Column A | Correct Answer |
|---|---|
| 1. Solute | C. Substance that gets dissolved |
| 2. Solvent | A. Liquid present in larger amount in a solution |
| 3. Saturated solution | E. Solution in which no more solute dissolves at that temperature |
| 4. Unsaturated solution | D. Solution in which more solute can still dissolve |
| 5. Solubility | B. Maximum amount of solute dissolvable at a given temperature |
Question 37 – Match the Following
| Column A | Column B |
|---|---|
| 1. Density | A. Instrument used to measure mass |
| 2. Relative density | B. Mass per unit volume |
| 3. Digital weighing balance | C. Curved surface of a liquid in a measuring cylinder |
| 4. Meniscus | D. Ratio of density of substance to density of water |
| 5. Water displacement method | E. Used to find volume of irregular solids |
Answer:
| Column A | Correct Answer |
|---|---|
| 1. Density | B. Mass per unit volume |
| 2. Relative density | D. Ratio of density of substance to density of water |
| 3. Digital weighing balance | A. Instrument used to measure mass |
| 4. Meniscus | C. Curved surface of a liquid in a measuring cylinder |
| 5. Water displacement method | E. Used to find volume of irregular solids |
