Acid Base And Salt

On completion of this lesson, students should be able to:

  • Define acid, base and salt.
  • Explain the characteristics of acid base and salt.
  • Describe the use of acid, base and salt in our daily life.
  • Differentiate acid and base.
  • Explain what are indicators and their use.



Substances which release hydrogen ions (H+ions) in aqueous solution or donates proton during chemical reaction are called acid. This note explains about types and properties of acid along with its uses.


Those compounds which release hydroxyl ion (Anion) in their aqueous solution are called base.For e.g. NaOH → Na+ + OH-, Ca(OH)2 → Ca++ + OH-, Mg(OH)2 → Mg++ + OH-, etc. This note has information on types of alkali, along with their uses and properties.


The neutral substance formed by the reaction between acidic radical and basic radical is known as salt. This note has explanation about salts how they are prepared and what are their uses.


Litmus, phenolphthalein and methyl orange are the common indicators which determine the acidic and basic nature of a substance by a characteristic change in their colour. This is note is detailed explanation of indicators used to distinguish acid and basic properties of compound.

pH Scale

The pH of a solution is defined as the measure of the H+ ions concentration present in the given solution. This is a short note on pH scale and how it is measured.