How do we differentiate between $Fe^{3+}$ and $Cr^{3+}$ in group $III$?

When a salt is treated with sodium hydroxide solution,it gives gas $X$. On passing gas $X$ through reagent $Y$,a brown-coloured precipitate is formed. $X$ and $Y$ respectively,are

When $H_2S$ gas is passed through a solution,it reacts to form a white precipitate. Which ion is present in the solution?

$A$ 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 sulphide is soluble in $(NH_4)_2CO_3$?

$A$ black sulphide is formed by the action of $H_2S$ on