Question

The number of species from the following which have square pyramidal structure is___
\(PF_5, BrF^− _4 4 − , IF_5\) ; \(BrF_5, XeOF_4, ICl ^−_ 4\)

Answer 1

Correct Answer: 3

The determination of molecular geometry is based on the VSEPR (Valence Shell Electron Pair Repulsion) theory. A square pyramidal structure corresponds to the AX₅E type, where:

• A = Central atom
• X = Bonded atoms
• E = Lone pairs of electrons 

Analysis of Each Species:

1. PF₅: Trigonal bipyramidal structure (AX₅), not square pyramidal.
2. BrF₄⁻: Square planar structure (AX₄E₂), not square pyramidal.
3. IF₅: Square pyramidal structure (AX₅E), as it has 5 bonded atoms and 1 lone pair.
4. BrF₅: Square pyramidal structure (AX₅E), as it has 5 bonded atoms and 1 lone pair.
5. XeOF₄: Square pyramidal structure (AX₅E), as it has 5 bonded groups (4 F and 1 O) and 1 lone pair.
6. ICl₄⁻: Square planar structure (AX₄E₂), not square pyramidal.

Conclusion:

Species with square pyramidal structures are:

• IF₅
• BrF₅
• XeOF₄

Answer: The number of species with a square pyramidal structure is 3.