What is a Mixture?
A Mixture is formed when two or more substances are combined physically.
- Key Feature: The components retain their original properties. They do not react chemically.
- Separation: Can usually be separated by physical methods (filtration, evaporation, magnetic separation).
Types of Mixtures
-
Non-Uniform (Heterogeneous) Mixtures:
- The components are visible with the naked eye.
- Examples: Sprout salad, Oil and water, Sand and iron filings.
-
Uniform (Homogeneous) Mixtures:
- The components are evenly distributed and cannot be seen separately.
- Examples: Sugar solution, Air, Alloys.
Special Examples of Mixtures
1. Air
Air is a uniform mixture of gases like Nitrogen (78%), Oxygen (21%), Argon, Carbon Dioxide, and Water Vapour.
- Proof: We can test for components separately (e.g., Lime water turns milky due to ).
2. Alloys
Alloys are uniform mixtures of metals (or metal and non-metal).
- Stainless Steel: Iron + Nickel + Chromium + Carbon.
- Brass: Copper + Zinc.
- Bronze: Copper + Tin.
Note
Did you know? Even though alloys look like a single substance, they are mixtures because their components are just mixed physically (melted together) and not chemically bonded in fixed stoichiometric ratios like compounds.
Table: Types of Mixtures
| State of Components | Example |
|---|---|
| Gas + Gas | Air |
| Gas + Liquid | Soda water (CO2 in water) |
| Solid + Gas | Smoke (Carbon particles in air) |
| Liquid + Liquid | Vinegar (Acetic acid in water) |
| Solid + Liquid | Salt water |
| Solid + Solid | Alloys (Brass, Bronze) |