JEE Chemistry 2023 Question with Solution

Given: The factors affecting the percent covalent character of an ionic bond are to be counted from the given options.

Find: The number of correct factors, and hence the correct options.

By Fajans' rule, covalent character in an ionic bond increases when the cation has high polarising power and the anion is easily distorted.

The relevant factors are:

1. Polarising power of the cation — a small, highly charged cation can polarise the anion electron cloud and increase covalent character.
2. Extent of distortion of the anion — greater distortion of the anion increases covalent character.
3. Polarisability of the anion — a more polarisable anion shows greater covalent character.

The polarising power of the anion does not contribute here.

Therefore, the correct factors are A, B, and C, so the number of such factors is $3$.

Given: The question asks for factors affecting covalent character in an ionic bond.

Find: The count of correct factors.

Use Fajans' rule directly:

• Small, highly charged cations increase polarisation.
• Large, easily distortable anions increase covalent character.

So the valid factors are cation polarising power, anion distortion, and anion polarisability.

Hence, the number of correct factors is $3$.