$A$ solution of a metal ion,when treated with $KI$,gives a red precipitate which dissolves in excess $KI$ to give a colourless solution. Moreover,the solution of the metal ion,on treatment with a solution of cobalt$(II)$ thiocyanate,gives rise to a deep blue crystalline precipitate. The metal ion is:

$A$ mixture of two salts is used to prepare a solution $S$,which gives the following results:
White precipitate$(s)$ $\xleftarrow{\text{Dilute } NaOH(aq.) \text{ at Room temperature}}$ $S$ (aq. solution of the salts) $\xrightarrow{\text{Dilute } HCl(aq.) \text{ at Room temperature}}$ White precipitate$(s)$ only
The correct option$(s)$ for the salt mixture is(are):
$A$. $Pb(NO_3)_2$ and $Zn(NO_3)_2$
$B$. $Pb(NO_3)_2$ and $Bi(NO_3)_3$
$C$. $AgNO_3$ and $Bi(NO_3)_3$
$D$. $Pb(NO_3)_2$ and $Hg(NO_3)_2$

In the group $III$ radicals,in place of $NH_4Cl$,which of the following can be used?

An aqueous solution of an inorganic salt on treatment with $HCl$ gives a white precipitate. This solution contains

Which of the following cations does not give a precipitate with $H_2S$ in a neutral medium?

When $H_2S$ is passed through a mixture containing $Cu^{2+}$,$Ni^{2+}$,and $Zn^{2+}$ in an acidic solution,which ion will precipitate?