Passage - 1 p-amino-N, N-dimethyl aniline is added to a strongly acidic solution of X. The resulting solution, when treated with a few drops of aqueous solution of Y, gives a blue color due to the formation of methylene blue. A thick blue precipitate is obtained when an aqueous solution of Y is treated with potassium hexacinoferrate (II). This precipitate dissolves by adding more of the reagent. Similarly, when a Y solution is treated with a potassium haxacinoferrate (III) solution, a brown colored solution is formed due to the formation of Z. Compound Y is