Answer: Axial bonds are perpendicular to 3 equatorial bond pairs (more repulsion, longer bond).
- A Axial bonds are perpendicular to 3 equatorial bond pairs (more repulsion, longer bond)
- B The chlorine atoms occupying axial positions are physically larger in the majority of cases studied
- C The phosphorus atom is somehow chemically different at each position as widely reported
- D The bond length difference arises mainly from the reaction temperature in standard practice
Correct answer: A. Axial bonds are perpendicular to 3 equatorial bond pairs (more repulsion, longer bond)
Explanation: Axial bonds in a trigonal bipyramid experience repulsion from three equatorial bonds at 90°; equatorial bonds only face two equatorial + two axial at 120° and 90° respectively.
Xenon tetrafluoride (XeF4) has six electron domains around xenon — four Xe–F bonds plus two lone pairs. The lone pairs occupy opposite axial positions, leaving the four fluorine atoms in a square-planar shape (Xe–F ≈ 194 pm). Image: ChemSim, Public Domain, via Wikimedia Commons.
Concept context
Covers the nitrogen family (Group 15), oxygen family (Group 16), halogens (Group 17), and noble gases (Group 18). One of the highest-weightage inorganic chapters in NEET and JEE - includes preparation and properties of HNO₃, H₂SO₄, interhalogens, and xenon compounds.