Question

An element ‘A’ exists as a yellow solid in standard state. It forms a volatile hydride ‘B’ which is a foul smelling gas and is extensively used in qualitative analysis of salts. When treated with oxygen. ‘B’ forms an oxide ‘C’ which is colourless, pungent smelling gas. This gas when passed through acidified KMnO₄ solution decolourises it. A, B and C are 

a) S, H₂S and SO₂ 

b) S, H₂S and SO₃ 

c) C, CH₄ and CO₂ 

d) C, C₂H₂ and CO₂

Answer 1

a) S, H₂S and SO₂ 

The element ‘A’ which exists as yellow solid is Sulphur. The volatile hydride ‘B’ is H₂S which has a rotten egg like smell. When treated with oxygen, the oxide formed is SO₂ which has a pungent smell. The gas when passed through acidified KMnO₄ decolourises it.