Chemistry Class IX (Matter)

A solution is a homogeneous mixture. It is not a chemical compound.

In Chemistry, a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. Mixture refers to the physical combination of two or more substances, the identities of which are retained and are mixed in the form of alloys, solutions, suspensions and colloids.

Air is an example of homogeneous mixture.

A pure substance cannot be separated into any other kinds of matter by any physical or chemical process. It is also made up of the same particles. An element is an example of a pure substance because it cannot be broken down into simpler substance.
Examples of pure substances would be: H₂O (water), neon (an element), and NaCl (table salt).

A homogeneous mixture is a type of mixture in which the composition is uniform. A heterogeneous mixture is a type of mixture in which the composition can easily be identified since there are two or more phases present. Air is a homogeneous mixture of the gaseous substances nitrogen, oxygen, and smaller amounts of other substances. Salt, sugar, and many other substances dissolve in water to form homogeneous mixture.

A homogeneous solution of a solid into another solid is called solid solution.

A mixture, which has different compositions and different properties at different locations is called heterogeneous mixture.

A homogeneous mixture of two or more substances is called solution.

A substance in which a solute is dissolved to obtain a solution is called solvent.

The size of particles in a suspension is greater than 10^-7 m.

A solution in which water is used as a solvent is called aqueous solution.

The solution obtained by dissolving a solute in any solvent other than water is called non aqueous solution.

Water is known as the universal solvent.

In a true solution, the size of solute particles is about 10^-10 m.

A substance which is dissolved to obtain a solution is called solute.

A solution in which the solvent is water is called aqueous solution. Solution of alcohol in water is an aqueous solution.

A solution in which no more solute can be dissolved at any fixed temperature is called saturated solution.

A solution in which some more solute could be dissolved at any fixed temperature is called unsaturated solution.

True solutions are example of homogeneous mixtures.

When a beam of light is passed through a colloidal solution, the light gets scattered. This is known as tyndall effect.

The size of a colloidal particle is 10^-9 - 10^-7 m.

Barium sulphate is used for diagnostic X-rays.

Salt solution is a true solution. True solutions do not show tyndall effect.

The movement of colloidal particles under the influence of electric field is called electrophoresis.

The scattering of light by the particles in a colloid is called tyndall effect.