Concept:Primary amines (\( \text{R-NH}_2 \)) share the same core structural geometry as ammonia (\( \text{NH}_3 \)), driven by \( \text{sp}^3 \) hybridization with one lone pair.
Formula:$$ \text{Type} = \text{AB}_3\text{E} $$
Solution:- In a primary amine, the central Nitrogen atom bonds to two Hydrogens and one Carbon group.
- It retains 1 lone pair of electrons.
- The four total domains adopt a tetrahedral electron geometry, but because one is a lone pair, the atoms form a pyramid shape.
- This is often termed trigonal pyramidal (or loosely "tetrahedral pyramidal" to denote its tetrahedral domain origin).
Why other options are incorrect:- Option A, Option C, Option D: These geometries ignore the physical space required by the nitrogen's lone pair, which forces the bonds out of a flat plane.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.