Question

Explain the following:

Ionic compounds have high melting and boiling points while covalent compounds have low melting and boil­ing points.

Answer 1

Ionic compounds are formed by the transfer of electrons.

• Ionic compounds have high melting and boiling points because there is a strong electrostatic force of attraction between the oppositely charged ions
• hence a large amount of energy is required to break the strong bonding force between ions.

Covalent compound: The chemical bond that is formed between two combining atoms by mutual sharing of one or more pairs of electrons is called a covalent bond and the compound formed due to this bond is called a covalent compound.

• Covalent bond has weak intermolecular forces, that is, the forces between molecules is very weak. So, it becomes easy to move individual molecules away from other molecules as the bonding between molecules is weak;

Hence it needs little energy to break. Since temperature is proportional to energy, that means the temperature required to melt the compound is low.