Chemistry - Class Twelve



Solutions: An Introduction

Homogeneous mixture of two or more components is called solution. For example – mixture of salt and sugar, mixture of oxygen and nitrogen, mixture of sugar in water, etc.

Homogeneous and Heterogeneous Mixture

Homogeneous mixture

A mixture of two or more components having no dinguish phase is called homogeneous mixture. Homogeneous mixture is generally referred as solution. For example – when two spoon of salt is mixed in a glass of water, the mixture so obtained has no distinguish phase and this is called solution. Air is mixture of different gases with no distinguish phase, thus, air is often referred as solution.

In homogeneous mixture, i.e. solution, the composition and properties of the solution are uniform throughout.

Heterogeneous mixture

A mixture of two or more components with distinguish phase is called heterogeneous mixture. For example – mixture of mustard oil and water, in this mixture phases of water and mustard oil can be seen and distinguised clearly, and hence called heterogeneouos mixture.

Solute and Solvent


Substance which is present in largest quantity in a solution; is generally referred as solvent. For example – In the solution of salt in water, since water is present in larger quantity, thus, water is called solvent. It is the solvent that decides the phase of a solution.


Substance which is present in lesser quantity in a solution, is generally called solute. In other words one or more components present in a solution other than solvent are is called solute. For example – in the solution of salt in water, salt is called solute. Solute may be more than one.

Binary Solution

Solutions which contain only two components are called binary solution. For example solution of salt in water is a type of binary solution, as it contain only two components.


Topics covered in this chapter of Solutions

1. Solutions

2. Types of Solutions

3. Solutions - Concentration

4. Solution of NCERT In Text Questions

Class 12 Biology

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