compound a is a light green crystalline solid. It gives the following tests
(i) It dissolves in dilute sulphuric acid. No gas is produced.
(ii) A drop of `KMnO_(4)` is added to the above solution. The pink colour disappears.
(iii) Compound A is heated strongly. Gases B and C, with pungent smell, come out. A brown residue D is left behind.
(iv) The gas mixture (B and C) is passed into a dichromate solution. The solution turns green.
(v) The green solution forms step (iv) gives a white precipitate E with a solution of barium nitrate.
(vi) Residue D from step (iii) is heated on charcoal in a reducing flame. It gives a magnetic substance.
Name the compound A, B, C, D and E.