The hybridization of NCl_3 and PCl_3 are respectively:

The correct answer is Option (1) → Both sp³

The hybridisation follows from the number of electron pairs (bond pairs + lone pairs) around the central atom:

• NCl₃: N has 5 valence electrons; 3 are used in the N–Cl bonds and 2 remain as one lone pair. 3 bond pairs + 1 lone pair = 4 pairs: sp³, pyramidal.

• PCl₃: P also has 5 valence electrons, giving 3 bond pairs + 1 lone pair = 4 pairs: sp³, pyramidal.

So both molecules are sp³ hybridised.

Why the other options are incorrect

• Option (2) Both sp³d — Incorrect. sp³d needs five electron pairs, as in \( \ce{PCl5} \); \( \ce{NCl3} \) and \( \ce{PCl3} \) have only four.

• Option (3) sp³d and sp³ — Incorrect. Nitrogen has no d orbitals in its valence shell, so it can never be sp³d hybridised.

• Option (4) sp³ and sp³d — Incorrect. Phosphorus uses its d orbitals only in \( \ce{PCl5} \); in \( \ce{PCl3} \) it has four electron pairs and is sp³.

Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.

NCERT (Pre-rationalised edition, 2022-23):
Properties