Class 8 Science Chapter 9, The Amazing World of Solutes, Solvents, and Solutions, begins with homemade Oral Rehydration Solution (ORS) to explain why every sip tastes the same, then explores solubility, saturated solutions, dissolved gases, floating and density.
What Class 8 Science Chapter 9 Covers
9.1 Solute, Solvent, and Solution and 9.2 How Much Solute Can Dissolve? define solute, solvent and solution, and investigate unsaturated and saturated solutions and how temperature affects solubility (Activities 9.1 and 9.2).
9.3 Solubility of Gases explains how oxygen dissolves in water to sustain aquatic life and why gas solubility decreases when water warms.
9.4 Why Do Objects Float or Sink? and 9.5 What Is Density? define density as mass per unit volume and measure mass and volume using balances and measuring cylinders (Activities 9.3 to 9.7).
Everyday examples: a solution is a uniform mixture such as salt or sugar in water: the solid is the solute and the liquid the solvent. The chashni of gulab jamun is a lot of sugar dissolved in a little water. A solution that can still dissolve more solute is unsaturated; once solute settles at the bottom it is saturated, and the maximum amount that dissolves is the solubility. The chapter ends with density and why objects float or sink.
Exercises in Chapter 9
- Keep the curiosity alive end-of-chapter questions and reasoning exercises.
- Discover, design, and debate and Projects for hands-on investigation.
Read Class 8 Science Chapter 9 Online
More Chapters
- Previous: Chapter 8: Nature of Matter: Elements, Compounds, and Mixtures
- Next: Chapter 10: Light: Mirrors and Lenses
- Hindi medium: Class 8 Science Chapter 9 PDF in Hindi (Jigyasa)
- All Science chapters and the other Class 8 books: Class 8 NCERT books 2026-27
- All Class 1 to 12 NCERT Textbooks: NCERT Books PDF (Class 1–12)
FAQ
How does temperature affect the solubility of solids and gases in water?
For most solids, solubility in water increases with temperature; for gases, solubility in water decreases as temperature rises.
What is the formula for density in Class 8 Science Chapter 9?
Density equals mass divided by volume (Density = Mass / Volume).
What is a saturated solution?
A solution in which no more solute can dissolve at that temperature, so extra solute settles at the bottom.