Given below are two statements — Assertion A and Reason R: Assertion A: Lithium halides are somewhat covalent in…
Chemical Bonding · Class 11 · JEE Main Previous Year Question
Given below are two statements — Assertion A and Reason R:
Assertion A: Lithium halides are somewhat covalent in nature.
Reason R: Lithium possesses high polarisation capability.
Choose the most appropriate answer:
- a
A is true but R is false
- b
A is false but R is true
- c
Both A and R are true but R is NOT the correct explanation of A
- d✓
Both A and R are true and R is the correct explanation of A
Both A and R are true and R is the correct explanation of A
🧠 Lithium () has the smallest ionic radius among alkali metal cations, giving it the highest charge density and polarizing power.
🗺️ Evaluate Assertion A:
Lithium halides show measurable covalent character compared to other alkali metal halides (LiI is notably covalent, soluble in organic solvents).
A is TRUE ✓
Evaluate Reason R:
ionic radius = 76 pm (smallest alkali metal cation). High polarizing power (∝ charge/radius) → distorts the anion electron cloud significantly → introduces covalent character in Li–X bonds (Fajans' rule 2: small cation increases covalent character).
R is TRUE ✓ and correctly explains A ✓
⚡ Even though all alkali metals have +1 charge, is special because its small size creates unusually high charge density, making LiX compounds measurably covalent.
Practice this question with progress tracking
Want timed practice with adaptive difficulty? Solve this question (and hundreds more from Chemical Bonding) inside The Crucible, our adaptive practice platform.
More JEE Main Chemical Bonding PYQs
Which one of the following molecules has maximum dipole moment?
Choose the polar molecule from the following:
Statement I: Dipole moment is a vector quantity and by convention it is depicted by a small arrow with tail on the negative centre and head pointing towards the positive centre. Statement II: The…
ClF5 at room temperature is a
The pair from the following pairs having both compounds with net non-zero dipole moment is