JEE Main 2026 — Practical Chemistry Question with Solution

An apple green colour in the flame test indicates the presence of $B{a}^{2+}$ ion.

The group precipitate of $B{a}^{2+}$ is $BaC{O}_3$, which dissolves in acetic acid to form barium acetate. Upon treatment with $K_{2}Cr{O}_4$, it gives a yellow precipitate of barium chromate ($BaCr{O}_4$), confirming the presence of $B{a}^{2+}$.

When the sodium carbonate extract is heated with conc. $HN{O}_3$ and ammonium molybdate, the formation of a canary yellow precipitate indicates the presence of phosphate ($P{O}_4^{3-}$) ion. The canary yellow precipitate is ammonium phosphomolybdate, $(N{H}_4{)}_{3}P{O}_4\cdot 12Mo{O}_3$.

Therefore, the cation is $B{a}^{2+}$ and the anion is $P{O}_4^{3-}$.

Answer: $B{a}^{2+}$ and $P{O}_4^{3-}$