A pinch of NH4Cl is added to original solution. On adding excess of NH4OH to make the solution alkaline then add freshly prepared (NH4)2CO3 solution, a white precipitate is obtained.
Ba2+ + CO32- → BaCO3
White precipitate is soluble in acetic acid.
BaCO3 + 2CH3COOH → Ba(CH3COO)2 + H2O
Add K2CrO4 solution. Formation of yellow precipitate indicates the presence of Ba2+.
Ba2+ + CrO42– → BaCrO4
You can also perform flame test either with the salt or white precipitate. It gives grassy green flame.