Question

What is the significance of a formula? Give an illustration.

Answer 1

Hint: A formula is the symbolic form of an element/ molecule or compound. It can be either a chemical (molecular) formula or a structural formula. Every compound has a formula that can be written as it takes up less space and gives an idea about the atoms of each element.

Complete answer:
The chemical formula is defined as the combination of variables and coefficients used to describe the element present and the number of atoms in each element. You can easily find out the element and atoms by looking at a chemical formula.
The significance of chemical formulas is that they are of utmost importance while writing chemical equations. It also enables the definition of the element name and the number of atoms it consists of.
For example, The chemical formula of Water is ${{H}_{2}}O$. By observing the formula, we can say that it has two hydrogen atoms and one carbon atom. Salt has the formula NaCl, consisting of one Sodium atom and one chlorine atom.
Ethanol has the formula ${{C}_{2}}{{H}_{5}}OH$ or it can also be written as ${{C}_{2}}{{H}_{6}}O$. The compound has 2 carbon atoms, 6 hydrogen atoms, and 1 oxygen atom.
Formulas are not only chemical but structural too.
The structural formula of the chemical compound is the detailed graphic representation of the molecular/chemical formula. It shows the three-dimensional arrangement of the compound. It gives a vivid idea of the bonds present between the carbon atoms and various groups.
For example, the structural formula of Water is:
$H-O-H$ Here, it shows the two bonds between oxygen and hydrogen.

Note:
The chemical formula of a compound enables us to find the oxidation number of the elements. Also, the number of atoms present in a group or element is determined by the valency of the opposite element or group. The valencies are cross multiplied to derive the chemical formula.