Which of the following statement(s) is( are) correct?
  • A
    Soluble sulphide gives black precipitate with $$AgNO_3$$ solution which is soluble in hot dilute nitric acid
  • B
    Soluble sulphide produces a yellow precipitate with a suspension of cadmium carbonate
  • C
    Sulphide ion reacts with sodium nitroprusside and gives a purple coloration
  • D
    Free $$H_2S$$ gas forms white precipitate with tetrahydroxido plumbate(II) solution

Solution

Option (A),(B),(C) are correct.
(a) $$S^{2-}+Ag^+\longrightarrow Ag_2S$$;
$$Ag_2S+HNO_3+AgNO_3+S+NO+H_2O$$
(b) $$S^{2-}+Cd^{2+}\longrightarrow CdS\downarrow(yellow)$$
(c) $$\begin{matrix}&&II&&II\\S^{2-}&+&Na_2[Fe{(CN)}_5NO^+]&\longrightarrow&Na_4[Fe{(CN)}_5NOS]\end{matrix}$$
(d) Free $$H_2S$$ gas forms black precipitate with tetrahydroxido plumbate(II) solution$$
{[Pb{(OH)}_4]}^{2-}+H_2S\longrightarrow PbS\downarrow(black)+2OH^-+2H_2O$$