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Moreover, the salt 'A' on heating with solid K_(2)Cr_(2)O_(7) and concentrated H_(2)SO_(4) produces deep red vapours which dissolve in sodium hydroxide solution forming a yellow solution. This yellow solution gives yellow precipitate with Ba((NO)_(3))_(2) solution. On the basis of the aforesaid characteristic informations answer the following question : Reaction involved in comprehension : 2Bi^(3+) (A)+3H_(2)S overset(H+) to Bi_(2)S_(3) darr ("black") (B) + 6H^(+) Bi_(2)S_(3)+8HNO_(3) to 2Bi (NO_(3))_(3) (C) +2NO +3S +4H_(2)O Bi^(3+) + 3OH^(-) overset(NaOH) to Bi(OH)_(3) darr ("white"), 2Bi(OH)_(3) ("white")+3[Sn(OH)_(4)]^(2-) to 2Bi darr (D) +3 [Sn(OH)_(6)]^(2-) Bi^(3+) + 3OH^(-) overset(Na_(4)OH) to Bi(OH)_(3) darr ("white"), Bi(OH)_(3)daar ("white")+3HCl to BiCl_(3)+3H_(2)O BiCl_(3)+H_(2)OtoBiOCl darr ("bismuth oxychloride") (E)+2HCl 4NaCl + K_(2)Cr_(2)O_(7)+3H_(2)SO_(4) ("conc.") to 2CrO_(2) Cl_(2) ("deep red vapours") + 2Na_(2)SO_(4)+K_(2)SO_(4)+3H_(2)O CrO_(2)Cl_(2) + 4OH^(-) to CrO_(4)^(2-) + 2Cl^(-) + 2H_(2)O CrO_(4)^(2-) +BaCrO_(4) darr (yellow) Which of the following statements is incorrect ?

Answer»

The black precipitate `'D'` is of bismuth.
The black precipitate `'D'` is of `Hg+ Hg(NH_(2))NO_(3)`
Aqueous solutin of `'A'` gives yellow precipitate with freshly prepared `10%` solution of pyrogallol.
Aqueous solution of `'A'` gives red precipitate with `8-`hydroxyquinoline `(5%)` and POTASSIUM iodide `(6M)` in acidic medium.

Solution :(A)`Bi^(3+)+3OH^(-)toBi(OH)_(3)darr,2Bi(OH)_(3)darr+[Sn(OH)_(4)]^(2-)to2Bi darr +3[Sn(OH)_(6)]^(2-)`
(B)is not correct as `'D'` is precipitate of bismuth.
(C ) `Bi^(3+) + C_(6)H_(3)(OH)_(3) to Bi(C_(6)H_(3)O_(3))darr ("yellow")+3H^(+)`
(D)`Bi^(3+)+C_(9)H_(7)ON + H^(+) +4I^(-) to C_(9)H_(7)ON.HBil_(4) darr` (red)


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