An analyst at a water company tests a sample of river water for halide ions. Before adding silver nitrate solution, the analyst acidifies the sample with dilute nitric acid, not dilute hydrochloric acid.
Why is dilute hydrochloric acid not used?
Its chloride ions would form a white precipitate with silver nitrate.
It would dissolve any silver halide precipitate that forms.
Its hydrogen ions would form a precipitate with the silver ions.
It would react with the halide ions, so no precipitate could form.
107 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.