The group reagent for analytical group $IV$ is:

Which of the following is soluble in yellow ammonium sulphide?

$A$ 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 $Hg(NO_3)_2$

Which of the following compounds is not soluble in hot dilute $HNO_3$?

$A$ pink coloured salt turns blue on heating. The presence of which cation is most likely?

The qualitative distinction of $ZnSO_4$ and $Al_2(SO_4)_3$ can be done by using the reagent