QA: Adding Hydrogen Peroxide to an Aqueous solution of a Salt
Matching exercise. Aqueous Hydrogen peroxide is added to a sample of chemical and the following observations noted.
Learn the observations made and the correct inferences that flashes.
| Green alkaline solution goes yellow | Chromium(III) to chromate(VI) |
| Brown ppt in alkaline solution | Lead (II) because brown ppt is PbO2 |
| Green ppt turns brown | Iron(II) hydroxide to Iron(III) hydroxide |
| Pale green solution turning yellow | Iron(II) becoming Iron(III) in acidic solution |
| Purple solution is decolourised | Manganate(VII) in acid solution |
| Brown solution or black ppt | Iodine from iodide in acid solution |
| Brown ppt | Manganate(VII) because MnO2 is the brown ppt. |