Board, JEE Main & NEET Previous Year Questions

How Chemical Bonding Is Tested

Chemical Bonding is one of the highest-yield chapters for both Boards and competitive exams. Year after year the same patterns reappear, so recognising them is half the battle.

Most frequently tested patterns:

1. Hybridization identification — given a molecule/ion, find the hybridization and shape (especially $XeF_n$, interhalogens, oxoanions).
2. VSEPR shape & bond angle comparison — ranking bond angles, identifying see-saw/T-shape/square-planar molecules.
3. MO bond order & magnetism — $O_2$ family ions, isoelectronic species, paramagnetic vs diamagnetic.
4. Dipole moment comparisons — $NH_3$ vs $NF_3$, identifying polar/non-polar molecules.
5. Resonance & bond order — fractional bond orders in oxoanions.
6. Octet exceptions and Fajans' rules — covalent character ordering.

Key Point: For competitive PYQs, the exam name is given in brackets. Where the exact year is not certain it is omitted intentionally — focus on the pattern, which is what repeats.

The 30 previous-year-style questions below are arranged from Board level through NEET to JEE Advanced. Attempt each one before checking the step-by-step explanation.