When a white crystalline compound 'X' is heated with `K_(2)Cr_(2)O_(7)` and concentrated `H_(2)SO_(4)` a red dish brown gas 'A' is evolved. On passing 'A' into caustic soda solution, a yellow coloured solution of 'B' is obtained. Neutralising the solution 'B' with acetic acid and on subsequent addition of lead acetate a yellow precipitate C is obtained. When 'X' is heated with NaOH a colourless gas is evolved and on passing this a gas into `K_(2)HgI_(4)` (Nessler's reagent) solution a reddish brown precipitate D is formed. Identify '(A), (B), (C), (D) and X. Write equations for the reactions involved.

Explanation

(X)-(NH)_(4) (Cl) . (A)-(C)_(0) (O)_(2) (Cl)_(2), (~B)-(Na)_(2) (CrO)_(2) (C)-(PbCrO)_(4)
FIGURE
Chromyl chioride reddish brown .(CrO)_(2) (Cl)_(2)+2 (NaOH)_(1) rarr (Na)_(2) (CrO)_(4)+2 (HCl).
yellow
Jead chromate yellow (C)
.(NH)_(4) (Cl)+(NaOH) rarr (NaCl)+(NH)_(3)+(H)_(2) (O).
.2 (~K)_(2) (Hgl)_(4)+(NH)_(2)+3 (KOH) rarr (NH)_(2) (HgO) . (HgI)_(+)+7 (~K) 1.
.+2 (H)_(2) (O).