An aqueous solution containing $FeSO_4$,$Al_2(SO_4)_3$,and chrome alum is treated with $Na_2O_2$ and heated,followed by filtration. The resulting products are:

Which of the following salts is insoluble in water at room temperature but soluble in boiling water?

$A$ colorless aqueous solution contains nitrates of two metals,$X$ and $Y$. When it was added to an aqueous solution of $NaCl$,a white precipitate was formed. This precipitate was found to be partly soluble in hot water to give a residue $P$ and a solution $Q$. The residue $P$ was soluble in aqueous $NH_3$ and also in excess sodium thiosulfate. The hot solution $Q$ gave a yellow precipitate with $KI$. The metals $X$ and $Y$,respectively,are

Which of the following reagents is used to detect the presence of $Fe^{3+}$ ions in a solution?

$Pb(CH_3COO)_2$ gives a precipitate of which color with $H_2S$?

Upon treatment with ammoniacal $H_2S$,the metal ion that precipitates as a sulfide is