JEE Main 2026 Apr 8 Shift 2, Chemistry Q3: Valence Shell Electron Pair Repulsion (VSEPR) Theory

JEE Main2026Apr 8, Shift 2Chemistry

Bromine trifluoride autoionizes to form $BrF_{2}^{+}$ and $BrF_{4}^{-}$ . The shapes of the cation and anion are respectively _____, and _____.

A
bent, square planar
B
linear, square planar
C
bent, see-saw
D
linear, tetrahedral

Solution

Apply VSEPR using the steric number (bond pairs + lone pairs) on Br.

$BrF_{2}^{+}$ : Br has $7$ valence electrons, minus $1$ for the positive charge $= 6$ ; two are shared with F atoms, leaving $4$ electrons as $2$ lone pairs. Steric number $= 2 + 2 = 4$ → $s p^{3}$ , AX $_{2}$ E $_{2}$ geometry: bent.

$BrF_{4}^{-}$ : Br has $7$ valence electrons plus $1$ for the negative charge $= 8$ ; four are shared with F atoms, leaving $4$ as $2$ lone pairs. Steric number $= 4 + 2 = 6$ → $s p^{3} d^{2}$ , AX $_{4}$ E $_{2}$ geometry: square planar (lone pairs occupy axial positions to minimize repulsion).

Concept behind this question

Valence Shell Electron Pair Repulsion (VSEPR) Theory Notes, formulas and examples →

Practice more Chemistry

Concept-wise practice with instant solutions on Fundamenthol.

Start practicing →

JEE Main 2026 Apr 8 Shift 2, Chemistry Q3: Valence Shell Electron Pair Repulsion (VSEPR) Theory

Concept behind this question

More previous year questions on Valence Shell Electron Pair Repulsion (VSEPR) Theory

Practice more Chemistry