JEE Advanced levelSingle correct optionDifficulty 3 of 3pn159
6.4g of sulphur is heated with an excess of hot concentrated sulphuric acid according to S+2HX2SOX43SOX2+2HX2O. Volume of SOX2 liberated at STP is (S = 32; molar volume 22.4 L/mol)
A13.44L
B8.96L
C6.72L
D4.48L
Answer: A
n(S) = 6.4/32 = 0.20 mol. The equation gives 3 mol SO2 per mol S, so n(SO2) = 0.60 mol. Volume = 0.60 x 22.4 = 13.44 L. Here S is oxidised (0 to +4) and H2SO4 is reduced (+6 to +4).