Q. Sulphur trioxide can be obtained by which of the following reactions?
A) H₂SO₄ + PCl₅ —(heat)→
B) CaSO₄ + C —(heat)→
C) Fe₂(SO₄)₃ —(heat)→
D) S + H₂SO₄ —(heat)→
Explanation
[Solution from source] Iron(III) sulphate decomposes on heating: Fe₂(SO₄)₃ → Fe₂O₃ + 3SO₃. Sulphur with hot concentrated H₂SO₄ gives SO₂, H₂SO₄ with PCl₅ gives chlorosulphonic acid/sulphuryl chloride, and CaSO₄ with carbon is reduced to CaS or SO₂, not SO₃. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.