Question

The high melting and boiling points of diamond are due to:
A. Its refractive index.
B. Its high IP value.
C. Giant polymer structure with strong covalent bonds.
D. Its high electronegativity.

Answer 1

Hint: We know that Diamonds has a strong molecular structure, which is bonded in a covalent network, and each carbon atom is joined to four other carbon atoms by covalent bonds.

Complete step by step answer: Now, we see how the solid is classified
Solids can be classified into four types namely,
Molecular solids: In molecular solids, van der Waals forces, hydrogen bonds, or both hold most of the atoms or small molecules.
Covalent network solids: In covalent network solid, all the atoms are held in place by covalent bonds.
Ionic solids: In ionic solids, oppositely charged ions are held together by electrostatic attractions that are very strong, comparable in strength to covalent bonds
Metallic solids: Metallic solids are formed by metal atoms and they have metallic bonding present in them.
We must remember that the diamond belongs to the class of the covalent network solid. In Diamond, the atoms are bonded covalently in a continuous, extended network. The strong binding forces that join all the adjacent atoms account for the extreme hardness of Diamond. They cannot be broken or abraded without breaking a large number of covalent chemical bonds. The stronger intermolecular forces contribute to the high melting point of Diamond
So, the correct answer is “Option C”.

Note: We also know about the details of intermolecular forces.
Intermolecular forces: Intermolecular forces are electrostatic in nature and include van der Waals forces and hydrogen bonds. Molecules in liquids are held together by intermolecular interactions, which are weaker than the intramolecular interactions that hold the atoms together within molecules and polyatomic ions. Higher the intermolecular forces are higher the melting and boiling point.
The three major types of intermolecular interactions are,
-Dipole-dipole interactions
-London dispersion forces
-Hydrogen bonds