Add dilute nitric acid, followed by silver nitrate solution. If a yellow precipitate forms, it shows the presence of iodide ions.
Category: Identification of Ions and Gases
Describe the test for nitrate ions.
Add aqueous sodium hydroxide and aluminium foil into a sample of the solution, and warm gently. If a pungent colorless gas is produced, which turns damp red litmus blue, it shows the presence of nitrate ions.
Describe the test for hydrogen gas.
Insert a lighted splint into a test tube of the gas. If the lighted splint is extinguished with a ‘pop’ sound, it shows the presence of hydrogen gas.
Describe the test for Cu2+ ions using aqueous sodium hydroxide.
Add a few drops of aqueous sodium hydroxide into a sample of the solution, followed by adding aqueous sodium hydroxide in excess. If a blue precipitate forms which is insoluble in excess of aqueous sodium hydroxide, it shows the presence of Cu2+ ions.
Aqueous sodium carbonate vs aqueous sodium chloride
Describe the test for sulfur dioxide gas.
Bubble the gas into acidified potassium manganate (VII) solution.
KMnO4 solution changes color from purple to colorless in the presence of sulfur dioxide gas.