Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Testing for chlorides (Cl^-), bromides (Br^-) and iodides (I^-)
21 practice questions
Practice questions
1–8 of 8 · Easy
Question 1
1 mark · Easy
Answer and see the solution →State why nitric acid is added before silver nitrate when testing a solution for halide ions.
Question 2
3 marks · Easy
Answer and see the solution →(a)[1 mark]Describe what should be added to a solution to test for chloride ions using silver nitrate.
(b)[2 marks]State which chemical is added first and explain why that order is important in the test.
Question 3
2 marks · Easy
Answer and see the solution →A student adds silver nitrate solution to acidified solutions of three unknown salts. She observes the following: - Salt A: forms a white precipitate - Salt B: forms a cream precipitate - Salt C: forms a yellow precipitate Calculate the number of different halide ions identified and state the expected observation for each positive test.
Question 4
2 marks · Easy
Answer and see the solution →Explain why hydrochloric acid must not be used instead of nitric acid when testing for halide ions with silver nitrate.
Question 5
3 marks · Easy
Answer and see the solution →The table shows the precipitates formed when different halide ions react with silver nitrate. Ion in solution Observation after adding silver nitrate Cl^- White precipitate Br^- Cream precipitate I^- Yellow precipitate Use the information in the table to answer the following questions.
(a)[1 mark]State the name and colour of the precipitate formed when a solution containing bromide ions is tested with silver nitrate.
(b)[1 mark]Identify which ion produces a yellow precipitate with silver nitrate.
(c)[1 mark]A student obtains a white precipitate when testing their solution with silver nitrate. Which halide ion is present?
Question 6
3 marks · Easy
Answer and see the solution →(a)[1 mark]State the observation when a solution containing iodide ions is tested with silver nitrate.
(b)[1 mark]State the observation when a solution containing chloride ions is tested with silver nitrate.
(c)[1 mark]State the observation when a solution containing bromide ions is tested with silver nitrate.
Question 7
1 mark · Easy
Answer and see the solution →State the reagent that must be added to a solution before silver nitrate to test for chloride, bromide, or iodide ions.
Question 8
2 marks · Easy
Answer and see the solution →A student adds silver nitrate to a solution to test for chloride ions. Before adding the silver nitrate, they add hydrochloric acid by mistake instead of another reagent. Explain, using your knowledge of chemical tests, why this mistake could affect the test result.