Chapter-9 Solutions — Online MCQ Test
SCIENCE (CURIOSITY) · CLASS 8th · Karnataka State Board
Practice Chapter-9 Solutions with a free chapter-wise online MCQ test.
This chapter covers: solute - solvent - solubility - saturated solution - unsaturated solution - concentration - colloids.
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Chapter-9 Solutions — Important Questions & Answers
What is a solution?
- A. A homogeneous mixture of solute and solvent
- B. A heterogeneous mixture that is always opaque
- C. A substance that dissolves in water
- D. A liquid that contains only water
Answer: A. A homogeneous mixture of solute and solvent
A solution is a homogeneous mixture where one substance (solute) is uniformly dispersed in another (solvent), forming a single phase.
A solution is a homogeneous mixture where one substance (solute) is uniformly dispersed in another (solvent), forming a single phase.
Which component is present in larger quantity in a solution?
- A. Solute
- B. Solvent
- C. Both in equal amounts
- D. Depends on the type of solution
Answer: B. Solvent
The solvent is the component present in larger quantity in a solution. It is the substance in which the solute dissolves.
The solvent is the component present in larger quantity in a solution. It is the substance in which the solute dissolves.
How does temperature generally affect the solubility of solid solutes?
- A. It decreases with increase in temperature
- B. It increases with increase in temperature
- C. It remains unchanged
- D. It depends on the color of the solute
Answer: B. It increases with increase in temperature
For most solid solutes, solubility increases with an increase in temperature. Heating provides more energy for solute molecules to dissolve.
For most solid solutes, solubility increases with an increase in temperature. Heating provides more energy for solute molecules to dissolve.
A sample shows the Tyndall effect. What can be concluded about it?
- A. It is a true solution
- B. It is either a colloid or a suspension
- C. It is definitely a suspension
- D. It contains no dissolved particles
Answer: B. It is either a colloid or a suspension
The Tyndall effect (light scattering) occurs in colloids and suspensions due to larger particles, not in true solutions where particles are too small.
The Tyndall effect (light scattering) occurs in colloids and suspensions due to larger particles, not in true solutions where particles are too small.
When we prepare a solution by dissolving salt in water, is the process of dissolving a physical or chemical change? Justify your answer based on NCERT concepts.
- A. Chemical change because a new substance is formed
- B. Physical change because the salt can be recovered by evaporating water; no new substance is formed
- C. Both physical and chemical change
- D. Neither physical nor chemical change
Answer: B. Physical change because the salt can be recovered by evaporating water; no new substance is formed
Dissolution is a physical change because the solute retains its chemical identity and can be recovered unchanged by evaporation; only the form and state change.
Dissolution is a physical change because the solute retains its chemical identity and can be recovered unchanged by evaporation; only the form and state change.