Question

A colourless (A) when place into water a heavy white turbidly of (B) solid (A) gives a close solution in conesolution in cone `HCI` when `HCI` solution is added to clear solution water ,(B) forms again (B) dissolves in dilute `HCI`. When `H_(2)S` is passed through a sespension of (A) or (B), a black precipitate (C ) forms , (C ) is insolves in yellow ammonium sulphide `(NH_(4))_(2)S` , cone `H_(2)SO_(4)` added to solid (A) liberates gas (D) gas (D) is water soluble and gives white precipitate with mercuric salts (E ) and not mercuric salt .The black precipitate (C ) dissolves in `HNO_(3), (1,1)` to give a solution to which `H_(2)SO_(4)` is added followed by addition of `NH_(4)OH` when a white precipitate (F) is formed (E ) gives a black ppt , (G) with solution of sodium stannite.
Compound (B ) is not soluble in
A. Tartaric ric acid
B. HCI
C. `HNO_(3)`
D. `H_(2)SO_(4)`

Answer 1

Correct Answer - a
`underset((A))(BiCI_(3)) +H_(2)O rarr underset("White ppt")(BiOCI darr) +underset((B))(2HCI)`
`underset((B))(BiOCI)+2HCI rarr underset((A))(BiCI_(3))+H_(2)O`
`2BiCI_(3) + 3H_(2)S rarr underset("Brown-black ppt")(Bi_(2)S_(3)darr) +6HCI`
`Bi_(2)S_(3) +8HNO_(3) rarr 2Bi(NO_(3))_(3) +3S darr +2NO +4H_(2)O`
`2Bi(NO_(3))_(3) + 3H_(2)SO_(4) rarr Bi_(2) (SO_(4))_(3) +6HNO_(3)`
`Bi_(2)(SO_(4))_(3) +6NH_(4)OH rarr underset((F))underset("White ppt") (2Bi(OH)_(3)darr) +3(NH_(4))_(2) SO_(4)`
`2Bi(OH)_(3) +3Na_(2)SnO_(2) rarr underset("Black ppt")underset((G))(2Bi) +3Na_(2)SnO_(3) +H_(2)O`
`2BiCI_(3) +3H_(2)SO_(4) rarr Bi_(2) (SO_(4))_(3) +underset((D))(6HCI)`
`Hg_(2)(NO_(3))_(2) +2HCI rarr underset((E))underset("White ppt")(Hg_(2)CI_(2)darr)+2HNO_(3)`