Chemical Formula with Solved Examples

Everything has its name so it has chemicals. In this article, we will learn the concept of the chemical formula which enables us to represent the atomic composition of a chemical.

What is the Chemical Formula?

The Chemical formula represents the chemical composition of the compound (substances that are composed of two more different atoms) like the chemical formula of water H₂O tells us that it is composed of two atoms of Hydrogen and one atom of Oxygen. It tells about the elements that constitute the compound. It is the ratio of the atom of the elements that combine to form compounds.

How to Write the Chemical Formula?

• In order to write the chemical formula of the compound, we need to know beforehand the chemical symbol of the elements that constitute the compound, and the valency of those elements.

• An atom that carries a positive charge is referred to as a cation and the atom which carries a negative charge is referred to as an anion. A Cation is written first and then it is followed by an anion.

• Now the charges carried by a cation and anion forming part of the compound will get crossed with each other and written in the form of a subscript to the chemical symbols.

Solved Examples

1. The Chemical formula of Nitric Acid

Nitric Acid is composed of two elements. One is hydrogen and the other is nitrate. The chemical symbol of Hydrogen is illustrated by H and the chemical formula of Nitrate is illustrated by NO^3- . Hydrogen carries a +1 charge (positive charge) while Nitrate carries a -1 charge (negative charge). As cation is written first followed by anion, Hydrogen will be written first followed by Nitrate.

As a result, the chemical formula of Nitric Acid is HNO₃.

2. The Chemical formula of Calcium Hydroxide

Calcium Hydroxide is composed of two elements. One is calcium and the other is hydroxide. The chemical symbol of calcium is illustrated by “Ca” and the chemical formula of hydroxide is illustrated by “OH-”. Calcium carries a +2 charge (positive charge) while Nitrate carries a -1 charge (negative charge). As caution is written first followed by anion, Calcium will be written first followed by hydroxide.