• The term neutralization is used for a reaction between an acid and a base or alkali.
Acid + base = salt + water
For example, HCI + NaOH→ NaCI + H2O
• Neutralization is a quantitative reaction.
A general definition is based on Bronsted & Lowry acid – base theory.
HA represents an acid and B represents a base. Z is an electric charge; negative for an anion, zero, or positive for a cation. When the reaction takes place in water and the base is the hydroxide ion, OH-, the reaction can be written as
When the acid has been neutralized there are no molecules of HA (or hydrogen ions produced by dissociation of the molecule) left in the solution. It follows that, in a neutralization reaction, the equivalents of base added must be equal to the equivalents of acid present initially. This stage of the reaction to be the equivalence point.
• In all cases : equivalents of an acid = equivalents of a base
• When neutralization point is reached, N1V1 = N2V2
End point is the point of completion of the reaction indicated by suitable indicator. Hence it has additional drop of titrating reagent but, we use
N1V1 = N2V2
