Aqueous solution of a salt 'A', when mixed with NaoH solution and warmed, a black precipitate is formed. Black ppt. is filtered and dissolved in dil. `H_(2)SO_(4)` solution. The resulting solution gives a chocolate coloured precipitate with potassium ferrocyanide solution. the filtrate obtained after filtering off the black precipitate, upon warming with Zn and NaOH evolves a pungent smelling gas. the resulting solution also responds to the ring test. the filtrate does not evolve any gas when it is boiled with urea in the presence of `H_(2)SO_(4)`.
Q. Salt 'A' consists of:

Options

A. `Cu^(2+)`
B. `Hg^(2+)` salt
C. `Cu^(+)`
D. `Pb^(2+)`

Answer

A

Explanation