Question

Which smell comes after burning of ferrous sulphate

Answer 1

They have a pungent androtten smell due to the burning of sulfur

Answer 2

So their color changes from light green to white. On further heating, anhydrous ferrous sulphate decomposes to form ferric oxide (Fe2O3), sulphur dioxide (SO2) and sulphur trioxide (SO3).

FeSO4.xH20 → FeSO4 (anhydrous) + xH20 (separating water of crystallization)

So, the result smells like burning sulphur.