A hydrated metallic salt(A), light green in colour on earful heating gives a white anhydrous residue(B). (B) is soluble in water and its aqueous solution reacts with No to give a dark brown compound (C). (B) gives a brown residue (D) and a mixture oftwo gases (E) and (F). The gaseous mixture when passed through an acidified `KMnO_4` solution dischanges the pink colour and when passed through acidified `BaCl_2` solution gave a white precipitate.
A may be

Options

A. `FeSO_4.7H_2O`
B. `ZnSO_4. 7H_2O`
C. `CuSO_4.5H_2O`
D. `FeCl_3. H_2O`

Answer

A

Explanation

`underset("(A)")(FeSO_4). 7H_2O overset(Delta) rarr underset("(B)")(FeSO_4)+ 7H_2O`
Neutral `FesO_4` gives bown ring test `C= [Fe(H_2O)_5NO] SO_4`
`FeSO_4 overset(Delta)rarr underset("(D)")(Fe_2O_3) + underset("(E)")(SO_2) + underset("(F)")(SO_3)`