Unit – I A

Solutions and its Types

Terminology of Solutions:

  • Solution is a homogeneous mixtures of two or more than two or more components. Solution has a single phase.
  • The component that is present in the largest quantity is known as solvent. Solvent determines the physical state in which solution exists.
  • One or more components present in the solution other than solvent are called solutes.
  • If the composition and properties are uniform throughout the mixture, the solution is called homogeneous solution.
  • The constituent particles of solution can not be separated by filtration, settling or centrifugal action.
  • If solution consists of two chemical components, the solution is called binary solution. If it contains three or four chemical components it is called ternary or quaternary solution.


Types of Solution on the Basis of Size of Solute Particles:

  • Depending upon the size of solute particles, the solutions are broadly classified into three types.

    a) Corse Solution:

    Such solutions are formed when the size of constituent particles is relatively bigger.

    e.g. a mixture of salt and sugar.

    b) Colloidal Solution:

    It is formed when the size of the particles dispersed in the solvent are in the range of 10-7 cm to 10-4 cm. The colloidal particles carry charge of the same nature, which is important for the stabilization of the solution.

    e.g. Ferric hydroxide sol

    c) True Solution:

    A true solution is defined as a homogeneous mixture of two or more substances, the composition of which is not fixed and may be varied within the certain limit.

    The size of the particles dispersed in the solvent is less than 10-4 cm.

    e.g. Solution of common salt in water.



Types of Solution on the Basis of Phases of Solute and Solvent:

  • Depending upon the phases of solute and solvent the solutions are broadly classified into three types.

    a) Gaseous Solutions:

  • Solute phase : solid, solvent phase : gas, Also known as solid in gas solutions. e.g. iodine in air
  • Solute phase : liquid, solvent phase : gas, Also known as a liquid in gas solutions. e.g. Chloroform in nitrogen
  • Solute phase : gas, solvent phase : gas, Also known as gas in gas solutions. e.g. Mixture of non-reacting gases (O2+ N2)

    b) Liquid Solutions:

  • Solute phase : solid, solvent phase : liquid, Also known as solid in liquid solutions. e.g. sugar in water
  • Solute phase : liquid, solvent phase : liquid, Also known as liquid in liquid solutions. e.g. ethanol in water
  • Solute phase : gas, solvent phase : liquid‘ Also known as gas in liquid solutions. e.g. carbon dioxide in water

    c) Solid Solutions:

  • Solute phase : solid, solvent phase : solid, Also known as solid in solid solutions. e.g. Alloys like brass, bronze
  • Solute phase : liquid, solvent phase : solid, Also known as a liquid in solid solutions. e.g. Amalgam of mercury with metal
  • Solute phase : gas, solvent phase : solid, Also known as gas in solid solutions. e.g. pumice stone, H2 gas in palladium

Types of Solutions

  • Sometimes solutions of liquid in gas and solid in gas are not considered as solutions because the mixture may not be homogeneous.

 

Next Topic