Types of mixtures
A mixture is a combination of two or more substances that are mixed together physically but not chemically. In a mixture-
- Each substance keeps its own properties.
- The substances can usually be separated by physical methods.
- The composition of a mixture can be changed.
Types of mixtures Based on the Dispersion of Components
Homogeneous mixture – The substances(components) are dispersed uniformly throughout. They cannot be seen separately. Example sugar solution
Heterogeneous mixture – The substances(components) are not uniformly dispersed. They components can be seen separately. Example sand and water mixture
Types of Mixtures Based on the Physical State of Their Components
Mixtures can be classified according to the physical states (solid, liquid, or gas) of the substances being mixed.
| Dispersed phase | Dispersing medium | Homogeneous/heterogeneous | Example |
| Solid | Solid | Homogeneous | Brass, Bronze |
| Heterogenous | Salt and sand, pebbles in mud | ||
| Solid | Liquid | Homogeneous | Salt in water, sugar in water |
| Heterogenous | Muddy water, sand in water | ||
| Solid | Gas | Homogeneous | Sublimated iodine vapour in nitrogen container |
| Heterogenous | Smoke, dust in air | ||
| Liquid | Solid | Homogeneous | Mercury in zinc(amalgam), hydrated salts (CuSO4.5H2O) |
| Heterogenous | Butter, jelly | ||
| Liquid | Liquid | Homogeneous | Alcohol in water |
| Heterogenous | Oil in water | ||
| Liquid | Gas | Homogeneous | Humidity in air, nasal spray |
| Heterogenous | Clouds, smog | ||
| Gas | Solid | Homogeneous | Hydrogen gas dispersed in palladium metal |
| Heterogenous | Pumice stone, styrofoam | ||
| Gas | Liquid | Homogeneous | Oxygenated water, chlorinated pool water |
| Heterogenous | Soda water, soapy foam | ||
| Gas | Gas | Homogeneous | Air |
| Heterogenous | Nil as gases mix in each other |
Special Types of Mixtures
Solution
A homogeneous mixture where one substance dissolves in another. Example: a salt solution
Suspension
A heterogeneous mixture in which solid particles are dispersed in a liquid and settle down on standing. Example: muddy water
Colloid
A mixture with very tiny particles that do not settle down easily. Example: milk
| Property | Solution | Colloid | Suspension |
| Nature of mixture | Homogeneous | Appears homogeneous but is actually heterogeneous | Heterogeneous |
| Particle size | Less than 1 nm | 1–1000 nm | More than 1000 nm |
| Can particles be seen? | No | No (without special instruments) | Often visible to the naked eye |
| Do particles settle on standing? | No | No | Yes |
| Can it be separated by filtration? | No | No (ordinary filtration) | Yes |
| Appearance | Clear and transparent | Cloudy or translucent | Opaque and cloudy |
| Shows Tyndall effect? (scattering of light) | No | Yes | Yes (strongly) |
| Examples | Salt in water, sugar in water | Milk, starch in water, fog | Sand in water, chalk powder |
MATCH THE TYPE OF MIXTURE WITH EXAMPLE
Solid in solid heterogeneous – Sand and sugar
Solid in liquid homogeneous – Sugar in water
Solid in solid homogeneous – Brass alloy
Solid in liquid heterogeneous – Sand and water
MATCH THE TYPE OF MIXTURE WITH EXAMPLE
Liquid in liquid homogeneous – alcohol in water
Gas in gas – Air
Gas in liquid homogeneous – Soda water
Liquid in liquid heterogeneous – Oil and water
MATCH THE TYPE OF MIXTURE WITH EXAMPLE
Liquid in Gas homogeneous – Humidity in air
Liquid in Gas heterogeneous – Clouds
Gas in Solid homogeneous – Hydrogen in Palladium
Gas in Solid heterogeneous – Pumice stone