Question

The number of interhalogens from the following having square pyramidal structure is :CIF3, IF7, BrF5, BrF3, I2CI6, IF5, CIF, CIF5

Answer 1

Correct Answer: 3

To determine the number of interhalogens with a square pyramidal structure, we need to analyze the molecular geometries of the given compounds. Interhalogens are typically formed between two different halogens. The geometry depends on the number of bonded pairs and lone pairs around the central atom, which can be understood using VSEPR (Valence Shell Electron Pair Repulsion) theory.

1. CIF₃: Chlorine trifluoride has 5 regions of electron density (3 bonds and 2 lone pairs) around the central chlorine atom. VSEPR theory predicts a ‘T-shaped’ geometry, not square pyramidal.
2. IF₇: Iodine heptafluoride has 7 bonds and no lone pairs. Its geometry is ‘pseudo-octahedral’, with a pentagonal bipyramidal shape. Not square pyramidal.
3. BrF₅: Bromine pentafluoride has 6 regions (5 bonds and 1 lone pair) around the central bromine atom, resulting in a square pyramidal structure.
4. BrF₃: Bromine trifluoride has 3 bonds and 2 lone pairs, leading to a ‘T-shaped’ geometry, not square pyramidal.
5. I₂Cl₆: This is not an interhalogen compound in the traditional sense; it forms a dimer with bridging chlorine atoms.
6. IF₅: Iodine pentafluoride has 5 bonds and 1 lone pair, leading to a square pyramidal shape.
7. CIF: Chlorine monofluoride is diatomic with a linear structure, not square pyramidal.
8. CIF₅: Chlorine pentafluoride has 5 bonds and 1 lone pair, adopting a square pyramidal structure.

In summary, the compounds with a square pyramidal structure are BrF₅, IF₅, and CIF₅. Thus, there are 3 interhalogens with a square pyramidal shape, which matches the provided range (3,3).