The correct option is A True
Compound (A) is a light green crystalline solid.
It is hydrated ferrous sulphate FeSO4.7H2O
Ferrous sulphate is dissolved in dil.sulphuric acid.
When KMnO4 is added ferrous sulphate is oxidized to ferric sulphate and Mn(VII) ions are reduced to Mn(II) ions. Hence, the pink colour of KMnO4 disappears. When ferrous sulphate is strongly heated, sulphur dioxide gas (compound B) , sulphur trioxide gas (compound C) and a residue of ferric oxide (compound D) are obtained.
2FeSO4strongheating−−−−−−−−→Fe2O3+SO2↑+SO3↑.
When the mnixture of sulphur dioxide and sulphur trioxide is passed through dichromate solution, sulphur dioxide reduces dichromate ion ions to green coloured Cr(III) ions.
Cr2O2−7+2H++3SO2→2Cr3++3SO2−4+5H2O
This solution containing sulphate ions on treatment with barium nitrate gives white ppt of barium sulphate which is compound E.
Ba(NO3)2+SO2+4→BaSO4↓whiteppt+2NO−3
When ferric oxide is heated with charcoal in reducing flame, it is reduced to iron.
Fe2O3+3Cheat−−→2Fe+3CO