Chemistry - Complete P-block Question with Solution | TestHub
U is the anhydride of sulphuric acid, obtained by dehydrating oleum. It reacts as : U + H₂O → H₂SO₄ ; U + HCl → X (chlorosulphuric acid) ; U + NH₃ → (NH₄)₂SO₄ (excess NH₃). U is a powerful oxidising and sulphonating agent. Calculate the number of CORRECT statements about U and X.
(i) In all the given reactions the oxidation state of sulphur does not change.
(ii) U is a trigonal planar molecule in the gaseous state.
(iii) X contains S in the +6 oxidation state.
(iv) U is a basic oxide.
(v) The reaction of U with water is highly exothermic.
Answer:
Solution:
U = SO₃, X = HSO₃Cl. (i) S stays +6 in all three reactions (T); (ii) SO₃(g) is trigonal planar (T); (iii) S is +6 in HSO₃Cl (T); (iv) SO₃ is an ACIDIC oxide (F); (v) SO₃ + H₂O is violently exothermic (T). Correct statements: (i), (ii), (iii), (v) = 4.
