Mixtures

The matter, we see around us, can be classified into 2 categories:
1. Pure substance
2. Mixture.

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Pure Substance

A pure substance consists of a single type of particles. Hence, it cannot be separated into other kinds of matter by any physical process.

Mixture

Mixtures are constituted by more than one kind of pure form of matter.The constituents are mixed in any proportion. Hence, mixtures has no chemical formula.

Example: Sugar can be separated from a sugar solution via evaporation. However, sugar itself is a substance which cannot be separated into its chemical constituents by physical process.

Depending upon the composition of the constituents, we can have 2 types of mixtures.
Homogeneous: solute and solvent together form 1 phase and no physical boundary is visible.
Heterogeneous: solute and solvent forms distinct phase and can be distinguished easily.

Characteristics of Mixtures

The characteristics of mixtures are given below:

1. Mixture has no fixed composition.
2. Energy is neither produced nor evolved while forming a mixture.
3. Mixture has no fixed melting point and boiling points.
4. Mixture retain the properties of its components.
5. Components of mixtures can be separated by simple physical methods.

Types of Mixtures

Solution
A solution is a homogeneous mixture of two or more substances. For example, lemonade, soda water, alloys, air, etc.

Colloid
Colloid is a heterogeneous mixture of two or more substances. Due to the relatively smaller size of particles, as compared to suspension, the mixture appears to be homogeneous. For example, milk, fog, jelly, etc.
We cannot see colloidal particles but these particles scatter light. This scattering of light is called the Tyndall effect.

Suspension
A suspension is a heterogeneous mixture in which the solute particles do no dissolve but remain suspended throughout the bulk of the medium. Particles of a suspension are visible to the naked eyes.

Purity of Matter:
Matter around us is not pure. There us various techniques which are used to separate the components of mixtures like, hand picking, winnowing, centrifugation, distillation, chromatography, etc.