The group of four basic radicals, CO^(2+) Nl^(2+) Mn^(2+) and Żn^(2+) have group reagent hydrogen sulphide in presence of NH.OH. These radicals are precipitated as sulphides which are insoluble in NH_(4)OH. Addition of HS increases the ionization of NH_4OH due to reaction of OH and H lon. NH_4OHharrNH_(4) + OHH_2S hArr2H+S^(2-) Salt (A) of above group cations having black colour treated with above reagent and produced compound (B), (B) on treatment with HCl and KCIO, again converted into (A) with the evolution of HS gas. (A) again treated with KCN gives a buff coloured ppt. (C) which dissolved in excess KCN and produced (D)QTo avoid the precipitation of hydroxides of Ni*, Co. Mn along with those of the third group cations, the solution should be

The group of four basic radicals, CO^(2+) Nl^(2+) Mn^(2+) and Żn^(2+)

1.	The group of four basic radicals, CO^(2+) Nl^(2+) Mn^(2+) and Żn^(2+) have group reagent hydrogen sulphide in presence of NH.OH. These radicals are precipitated as sulphides which are insoluble in NH_(4)OH. Addition of HS increases the ionization of NH_4OH due to reaction of OH and H lon. NH_4OHharrNH_(4) + OHH_2S hArr2H+S^(2-) Salt (A) of above group cations having black colour treated with above reagent and produced compound (B), (B) on treatment with HCl and KCIO, again converted into (A) with the evolution of HS gas. (A) again treated with KCN gives a buff coloured ppt. (C) which dissolved in excess KCN and produced (D)QTo avoid the precipitation of hydroxides of Ni*, Co. Mn along with those of the third group cations, the solution should be
Answer» heated with few drops of CONC. `HNO_(3)` heated with excess of `NH_4`CI concentrated to SMALL volume NONE of the above Answer :b