Identify carbonate, sulfate and halide ions using appropriate tests.

In the subtopic Aqueous ion tests (A-level only), this AQA A-Level Chemistry 7405 learning objective focuses on identify carbonate, sulfate and halide ions using appropriate tests. It belongs to Reactions of ions in aqueous solution (A-level only), so revision should stay anchored to this exact subtopic rather than drifting into a generic GCSE-level chemistry summary. Approved keywords to use include carbonate, sulfate, halide. Carbonate ion test. means to identify carbonate ions, add dilute acid to the sample; if carbon dioxide is produced, it indicates the presence of carbonate ions Avoid the mistake of students often confuse the tests for halide ions, mistakenly using silver nitrate for sulfates instead of halides; instead, to correctly identify halide ions, use the test with silver nitrate. The reaction is: AgNO3 + NaCl → AgCl (white precipitate). Ensure to remember that barium chloride is used for sulfate tests For exam answers, to identify halide ions, add a few drops of dilute nitric acid followed by a few drops of silver nitrate solution. Observe the color of the precipitate formed