A sample of green crystals is tested using the procedures below. First, the crystals are dissolved in water, and the solution obtained is split into two parts. • Aqueous sodium hydroxide is added to the first part. A green precipitate, which dissolves in excess aqueous sodium hydroxide, is produced. The solution formed is warmed, and a gas is given off that turns litmus paper blue. • Dilute nitric acid is added to the second part, then aqueous barium nitrate is added. A white precipitate is produced. Which three ions are present in the green crystals?
- Aammonium, chromium(III), sulfate
- Bammonium, iron(II), sulfate
- Cchromium(III), carbonate, sulfate
- Diron(II), nitrate, sulfate