Bromine trifluoride autoionizes to form BrF2 and BrF4 . The shapes of the cation and anion are respectively and .
- bent, square planar
- linear, square planar
- bent, see-saw
- linear, tetrahedral
Answer
(1) bent, square planar
Solution
2BrF3 BrF2 + BrF4 (Br has 7 valence electrons)
BrF2 : electron pairs = 7 + 2 - 12 = 4 ⇒ 2 bond pairs + 2 lone pairs (sp3) ⇒ bent (V-shaped)
BrF4 : electron pairs = 7 + 4 + 12 = 6 ⇒ 4 bond pairs + 2 lone pairs (sp3d2); the two lone pairs occupy trans (axial) positions ⇒ square planar
Answer: (1)