Chemistry - Redox Reactions Question with Solution | TestHub
A quantity of 8.0 g of solid sulphur is first oxidized to SO₂ and then it is divided into two equal parts. One part is sufficient for complete decolourization of 200 ml of acidified KMnO₄ solution. Another part is oxidized to SO₃ and the SO₃ formed is sufficient for complete precipitation of all BaCl₂ present in 100 ml solution as BaSO₄. Which of the following statements is/are correct? (S = 32, Ba = 138)
Options:(select one or more)
Answer:
Solution:
8.0 g S = 0.25 mol 0.25 mol SO₂, split into 0.125 mol halves. First half: SO₂ (S +4 +6, n = 2) gives 0.25 g-eq, so KMnO₄ (n = 5) = 0.05 mol in 200 ml = 0.25 M - (a) true. Second half: 0.125 mol SO₃ 0.125 mol BaSO₄ = 0.125 x 234 = 29.25 g - (c) true; BaCl₂ = 0.125 mol in 100 ml = 1.25 M, not 0.25 M - (b) false. Equivalents: KMnO₄ 0.25 g-eq vs BaCl₂ 0.125 mol x 2 = 0.25 g-eq - equal, (d) true. Hence (a), (c), (d).
