A student wants to find out whether a solution contains sulfate ions and whether it contains chloride ions.
The student adds dilute hydrochloric acid and then barium chloride solution to a sample of the solution. A white precipitate forms.
The student filters the mixture. The student then adds dilute nitric acid and silver nitrate solution to the filtrate. A white precipitate forms.
The student concludes that the solution contains sulfate ions and chloride ions.
Which statement is correct?
Both conclusions are valid, because both tests gave a white precipitate.
Only the sulfate conclusion is valid, because chloride ions were added to the sample in the first test.
Only the chloride conclusion is valid, because barium chloride gives a white precipitate with any solution.
Neither conclusion is valid, because nitric acid removes chloride ions from the filtrate.
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.