Among $PbS$,$CuS$,$HgS$,$MnS$,$Ag_2S$,$NiS$,$CoS$,$Bi_2S_3$,and $SnS_2$,the total number of black coloured sulphides is

Mark the compound which turns black with $NH_4OH$.

The ion that cannot be precipitated by both $HCl$ and $H_2S$ is

Which of the following sulfides is completely precipitated upon dilution of its acidic solution?

Which ions can be separated using concentrated $NaOH$?

$M^{n+}(aq.) + KI \to X\downarrow \text{ (ppt.)}$ $\xrightarrow{Excess KI} \text{ppt. remains insoluble in excess } KI \text{ solution. Then cation } M^{n+}(aq.) \text{ can be}$