A student tests a solution for halide ions. The student adds an acid and then silver nitrate solution.
Why should the student use dilute nitric acid and not dilute hydrochloric acid?
Hydrochloric acid reacts with silver nitrate to give off chlorine gas.
Nitric acid makes the colour of the precipitate much easier to see.
Nitric acid reacts with the halide ions to form the precipitate.
Hydrochloric acid contains chloride ions, so it gives a precipitate.
52 exam-style questions on OCR GCSE Chemistry 4.2 Identifying the products of chemical reactions, covering 4.2.1 Tests to identify gases, 4.2.2 Tests for aqueous ions and flame tests, and 4.2.3 Instrumental methods of analysis. Each one has a worked solution and a mark scheme showing where the marks go.