True Solution Preparation MCQs Quiz | Class 9

Class IX Science (Code 086) Practicals (Unit I) quiz covering the preparation of true solutions of common salt, sugar, and alum. Test your understanding of solute-solvent interactions, solution characteristics, and stability. Attempt these 10 MCQs, submit to view your result, and download the comprehensive answer key PDF.

True Solution Preparation: Concepts & Characteristics

A true solution is a homogeneous mixture of two or more substances. In this practical unit, we focus on preparing solutions using common solutes like common salt (Sodium Chloride), sugar (Sucrose), and alum (Potash Alum) in water.

1. Key Characteristics of a True Solution

  • Homogeneous Nature: The composition is uniform throughout the mixture.
  • Particle Size: The solute particles are extremely small, typically less than 1 nm (10-9 m) in diameter.
  • Transparency: True solutions are clear and transparent; they do not scatter light (no Tyndall effect).
  • Filtration: Solute particles cannot be separated from the solvent by filtration as they pass through filter paper.
  • Stability: The particles do not settle down when left undisturbed.

2. Components of a Solution

A solution consists of two main components:

  • Solute: The substance that is dissolved (e.g., salt, sugar, alum). usually present in a smaller quantity.
  • Solvent: The medium in which the solute is dissolved (e.g., water). usually present in a larger quantity.

3. Comparison Table

Property True Solution Colloidal Solution Suspension
Particle Size < 1 nm 1 nm – 100 nm > 100 nm
Appearance Transparent Translucent Opaque
Stability Stable Stable Unstable
Tyndall Effect No Yes Yes (until settled)

4. Quick Revision Points

  • Water is known as the universal solvent because it dissolves many substances.
  • Stirring and increasing temperature generally increase the rate of dissolution for solids in liquids.
  • A solution where water is the solvent is called an aqueous solution.
  • Alum (Phitkari) is often used in water purification processes.

5. Extra Practice Questions

  1. Q: What happens to the boiling point of water when salt is added?
    A: It increases.
  2. Q: Can we see the particles of sugar in a sugar solution with a microscope?
    A: No, they are too small.
  3. Q: Is a true solution heterogeneous or homogeneous?
    A: Homogeneous.
  4. Q: Which method can separate salt from a salt solution?
    A: Evaporation or Distillation.
  5. Q: Does a true solution leave residue on filter paper?
    A: No residue is left.