A mixture of two salts is used to prepare a solution $S$, which gives the following results: White…

$\mathrm{P}{\mathrm{b}}^{2+}\stackrel{\mathrm{dil}.\mathrm{HCl}}{\to }{\mathrm{PbCl}}_2$(white precipitate)

$\mathrm{P}{\mathrm{b}}^{2+}\stackrel{\mathrm{dil}.\mathrm{NaOH}}{\to }\mathrm{Pb}{\left(\mathrm{OH}\right)}_2$(white precipitate)

${\mathrm{Bi}}^{3+}\stackrel{\mathrm{dil} \mathrm{HCl}}{\to }{\mathrm{BiCl}}_3$(water-soluble)

${\mathrm{Bi}}^{3+}\stackrel{\mathrm{dil}. \mathrm{NaOH}}{\to }\mathrm{Bi}{\left(\mathrm{OH}\right)}_3$(white precipitate)

${\mathrm{Hg}}^{2+}\stackrel{\mathrm{dil}.\mathrm{HCl}}{\to }{\mathrm{HgCl}}_2$(water-soluble)

${\mathrm{Hg}}^{2+}\stackrel{\mathrm{dil}. \mathrm{NaOH}}{\to }\mathrm{Hg}{\left(\mathrm{OH}\right)}_2$(yellow precipitate)

${\mathrm{Ag}}^{+}\stackrel{\mathrm{dil}. \mathrm{HCl}}{\to }\mathrm{AgCl}$(white precipitate)

${\mathrm{Ag}}^{+}\stackrel{\mathrm{dil}. \mathrm{NaOH}}{\to }\mathrm{AgOH}$(brown precipitate)

${\mathrm{Zn}}^{2+}\stackrel{\mathrm{dil}. \mathrm{HCl}}{\to }{\mathrm{ZnCl}}_2$(water-soluble)

${\mathrm{Zn}}^{2+}\stackrel{\mathrm{dil} .\mathrm{NaOH}}{\to }\mathrm{Zn}{\left(\mathrm{OH}\right)}_2$(white precipitate)