Explain the types of solutions based on physical state, the solvent and the amount of solute, with examples.

1. 1 · Define the terms. A solution is a homogeneous mixture of a solute (smaller amount) and a solvent (larger amount).
2. 2 · Based on physical state. Solute and solvent can each be solid, liquid or gas, giving nine types.
3. 3 · Draw the table of nine types. [Table: solute, solvent, example for all nine pairs, from alloys (solid in solid) to air (gas in gas)]
4. 4 · Based on the solvent. Aqueous (water is the solvent: salt in water). Non-aqueous (other solvents: sulphur in carbon disulphide).
5. 5 · Based on the amount of solute.
   • Unsaturated: can dissolve more solute at that temperature
   • Saturated: cannot dissolve more solute at that temperature
   • Supersaturated: holds more than the saturated amount; unstable
6. 6 · Real-life link. Soda water (gas in liquid), air (gas in gas), brass (solid in solid) and nimbu pani (solids in liquid) are all solutions.
7. 7 · Close in one line. Thus solutions are classified in three ways, each with its own examples.

Scoring tip: A neat nine-row table with one example each scores well. Write 'at a given temperature' for saturated and supersaturated.