Types of Solutions
NCERT Reference:Chapter 1 – Solutions – Page 1
Quick Notes
- Solution: A homogeneous mixture of two or more substances.
- Solute: Substance present in smaller amount.
- Solvent: Substance present in larger amount; dissolves the solute.
- Classification based on physical state:
- Gaseous solutions (e.g., air): gas in gas, gas in liquid.
- Liquid solutions (e.g., alcohol in water): solid/liquid/gas in liquid.
- Solid solutions (e.g., alloys): solid in solid.
Full Notes
Solutions are homogeneous mixtures – mixtures that have uniform composition and properties throughout.
They consist of two key components:
- Solute: the substance dissolved (typically in lesser amount).
- Solvent: the substance doing the dissolving (typically in greater amount).
Depending on the physical states of the solute and solvent, solutions are broadly classified into three main types:
Gaseous Solutions
These have gases as solvents.
Examples:
- Gas in gas: Oxygen in nitrogen (air).
- Liquid in gas: Water vapour in air (humidity).
- Solid in gas: Camphor sublimes into air.
Liquid Solutions
Liquids act as solvents.
Examples:
- Gas in liquid: Carbon dioxide in soft drinks.
- Liquid in liquid: Ethanol in water.
- Solid in liquid: Glucose or salt in water.
These are the most commonly encountered solutions in everyday life.
3. Solid Solutions
Solids act as solvents.
Examples:
- Gas in solid: Hydrogen in palladium used for catalytic purposes.
- Liquid in solid: Mercury in sodium (an amalgam).
- Solid in solid: Alloys like bronze (Cu + Sn), brass (Cu + Zn).
Key Characteristics of Solutions
- Solutions are homogeneous and stable.
- The solute particles cannot be seen with the naked eye.
- The solute does not settle out over time.
- Solutions can pass through filter paper without being separated.
Summary
- A solution is a homogeneous mixture made of a solute and solvent.
- Solutions are classified by the physical states of solute and solvent.
- Gaseous, liquid and solid solutions each have common real-world examples.
- Solutions are stable homogeneous mixtures that do not separate on standing.