Which of the following sulphides is yellow in colour?

Addition of sodium thiosulphate solution to a solution of silver nitrate gives $X$ as a white precipitate,which is insoluble in water but soluble in excess thiosulphate solution to give $Y$. On boiling in water,$Y$ gives $Z$. $X$,$Y$,and $Z$ respectively are:

Which of the following pairs cannot be separated by passing $H_2S$ gas?

$A$ (Orange color compound) $\xrightarrow{(B) + \text{conc. } H_2SO_4}$ $C$ (Red gas) $\xrightarrow{NaOH + AgNO_3}$ $D$ (Red ppt.) $\xrightarrow{\text{NH}_3 \text{ solution}}$ Yellow solution.
$B$ $\xrightarrow[\Delta]{NaOH}$ $F \uparrow$ (Gives white fumes with $HCl$).
Identify $B$ and $F$ respectively :-

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

Which of the following reagents is commonly used to detect the presence of sulfide ions?