Answer: V2O5 (vanadium pentoxide).
- A V2O5 (vanadium pentoxide)
- B Pt gauze, the catalyst used instead in the Ostwald process
- C Fe, the catalyst used instead in the Haber process
- D MnO2, used instead as a catalyst in oxygen generation from KClO3
Correct answer: A. V2O5 (vanadium pentoxide)
Explanation: V2O5 catalyses the oxidation 2SO2 + O2 → 2SO3 at 400-500°C; it replaced the older platinum catalyst as it is cheaper.

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.