Anions are negatively charged ions. They can be detecting in solution.
Add acidified silver nitrate, this is used to remove any, carbonate, sulphite or hydrogen ions present as they also produce a precipitate with silver nitrate. With this the halides form:
A white precipitate when Chloride ions are present.
A cream precipitate when Bromide ions are present.
A yellow precipitate when Iodide ions are present.
The ‘pH’ test will show up alkaline when Hydroxide ions are…