Neutralisation Reaction

These notes are based on the chapter Acids Bases and Salts from NCERT book based on CBSE syllabus.

The reaction between an acid and a base is called neutralisation reaction. Whan an acid reacts with a base then salt and water are formed. Such reaction is called neutralisation reaction. Following is the general equation for neutralisation reaction.

Acid + Base ⇨ Salt + Water

Examples of Neutralisation Reaction

Since in the reaction between acid and base both neutralize each other, hence it is also known as neutralization reaction. In this reaction, acid removes basic property of a base, and base removes acidic property of an acid or acid and base neutralise each other.

Example 1: What happens when hydrochloric acid reacts with sodium hydroxide? Sodium chloride and water are formed when hydrochloric acid reacts with sodium hydroxide (a strong base).

HCl + NaOH ⇨ NaCl + H₂O

Example 2: What happens when hydrochloric acid reacts with calcium hydroxide? Calcium chloride is formed along with water when hydrochloric acid reacts with calcium hydroxide (a base).

2HCl + Ca(OH)₂ ⇨ CaCl₂ + 2H₂O

Example 3: What happens when sulphuric acid reacts with sodium hydroxide? Sodium sulphate and water are formed when sulphuric acid reacts with sodium hydroxide (a base).

H₂SO₄ + 2NaOH ⇨ Na₂SO₄ + 2H₂O

Example 4: What happens when nitric acid reacts with sodium hydroxide? When nitric acid reacts with sodium hydroxide, sodium nitrate and water are formed.

HNO₃ + NaOH ⇨ NaNO₃ + H₂O

Reaction of Acid with Metal Oxides

Metal oxides are basic in nature. So, when an acid reacts with a metal oxide both neutralize each other. In this reaction, salt and water are formed. Reaction between acid and metal oxide is an example of neutralisation reaction.

Acid + Metal Oxide ⇨ Salt + Water

Example 1: What happens when hydrochloric acid reacts with calcium oxide? Calcium is a metal, thus calcium oxide is a metallic oxide which is basic in nature. When an acid (such as hydrochloric acid) reacts with calcium oxide, neutralization reaction takes place and calcium chloride, along with water, is formed.

2HCl + CaO ⇨ CaCl₂ + H₂O

Example 2: What happens when sulphuric acid reacts with zinc oxide? When sulphuric acid reacts with zinc oxide, zinc sulphate and water are formed.

H₂SO₄ + ZnO ⇨ ZnCl₂ + H₂O

Example 3: What happens when hydrochloric acid reacts with aluminium oxide? When hydrochloric acid reacts with aluminium oxide, aluminium chloride and water are formed.

Al₂O₃ + 6HCl ⇨ 2AlCl₃ + 3H₂O