Question

The most ionic compound among the following is,
A) Silica.
B) Aluminium Fluoride.
C) Carborundum.
D) Aluminium chloride

Answer 1

We know that in ionic solids, oppositely charged ions are held together by electrostatic attractions that are very strong, comparable in strength to 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.
Silica dioxide belongs to the class of the covalent network solid. In Silica dioxide, 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 Silica dioxide.
Therefore, option A is incorrect.
Carborundum is also called silica carbide. Silica carbide belongs to the class of the covalent network solid.
Therefore, option C is incorrect.
In aluminum fluoride, we have the most electronegative element fluorine and aluminum is the electropositive. Thus the most ionic compound is aluminum fluoride.
Therefore, option B is correct.
Chlorine is less electronegative than fluorine hence it is partially ionic and partially covalent. Therefore, option D is incorrect.

So, the correct answer is Option B.

Note:
Now we discuss the 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. The 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