The colour of copper sulphide is

The reagent that can distinguish between silver and lead salt is

$A$ colourless crystalline salt $X$ is soluble in dilute $HCl$. On adding $NaOH$ solution,it gives a white precipitate which is insoluble in excess of $NaOH$. $X$ is

Which ion is not precipitated by both $HCl$ and $H_2S$?

An aqueous solution contains the ions as $Hg_2^{2+}$,$Hg^{2+}$,$Pb^{2+}$,and $Cd^{2+}$. The addition of dilute $HCl$ $(6 \ N)$ precipitates:

Which reagents are used for the identification of Group $IV$ cations?