Chemistry - Salt Analysis Question with Solution | TestHub

Two salts 'P' & 'Q' form coloured ppt. with ${\mathrm{H}}_2\mathrm{S}$ in dil. HCl medium. One of the precipitate is yellow in colour & other is black which do not dissolve in ${\left({\mathrm{NH}}_4\right)}_2{\mathrm{S}}_2$. Salt ' Q ' gives a bluish-white ppt. with ${\mathrm{K}}_4\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]$ but the same salt when treated with excess ${\mathrm{NH}}_4\mathrm{OH}$ gives colourless solution. Salts 'P' & 'Q' form complexes with KCN with one of the complex converting to yellow ppt. on treatment with ${\mathrm{H}}_2\mathrm{S}$. Salts 'P' and 'Q' are