JAMB - Chemistry (1980 - No. 42)
Which of the following tests would confirm-unequivocally that a solution X contain the sulphate ion if it gives with?
silver nitrates solution, a white precipates insoluble in dilute HNO3
barium chloride solution, a white precipitate insoluble in dilute H2SO4
barium chloride solution, a white precipitate soluble in dilute HCl
barium chloride solution a white precipitate soluble in dilute ammonia
barium chloride solution a white precipitate insoluble in dilute HCl
Explicação
Sulfate ions in solution are detected using barium chloride solution.
The test solution is acidified using a few drops of dilute hydrochloric acid, and then a few drops of barium chloride solution are added.
A white precipitate of barium sulfate forms if sulfate ions are present.