Which sulphide is soluble in $(NH_4)_2CO_3$?

$Al^{3+}$,$Fe^{3+}$,$Zn^{2+}$,and $Ni^{2+}$ ions are present in an acidic solution. Excess of ammonium chloride $(NH_4Cl)$ solution is added followed by the addition of ammonium hydroxide $(NH_4OH)$ solution. The resulting precipitate will contain:

Among $Fe^{3+}$,$Pb^{2+}$,$Cu^{2+}$,and $Mn^{2+}$,identify the one that gets precipitated out while passing $H_2S$ gas in the presence of $NH_4OH$ as a group reagent. The highest possible oxidation state of the corresponding metal is:

$Pb^{2+}$,$Cu^{2+}$,$Zn^{2+}$,and $Ni^{2+}$ ions are present in a given acidic solution. On passing hydrogen sulphide gas through this solution,the precipitate formed will contain:

The reagents $NH_4Cl$ and aqueous $NH_3$ will precipitate which of the following ions?

How do we differentiate between $Fe^{3+}$ and $Cr^{3+}$ in group $III$?