A mixture of two salts is used to prepare a solution S, which gives...

$P{b}^{2 +}\overset{dil . HCl}{\to}{PbCl}_{2}$(white precipitate)

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

${Bi}^{3 +}\overset{dilHCl}{\to}{BiCl}_{3}$(water-soluble)

${Bi}^{3 +}\overset{dil . NaOH}{\to}Bi{\left(OH\right)}_{3}$(white precipitate)

${Hg}^{2 +}\overset{dil . HCl}{\to}{HgCl}_{2}$(water-soluble)

${Hg}^{2 +}\overset{dil . NaOH}{\to}Hg{\left(OH\right)}_{2}$(yellow precipitate)

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

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

${Zn}^{2 +}\overset{dil . HCl}{\to}{ZnCl}_{2}$(water-soluble)

${Zn}^{2 +}\overset{dil . NaOH}{\to}Zn{\left(OH\right)}_{2}$(white precipitate)