Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Testing for carbonates (CO3^2-)
20 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →A student is given a solution that may contain sodium carbonate. Describe two distinct observations the student would expect to make when dilute hydrochloric acid is added to this solution if carbonate ions are present.
Question 2
5 marks · Hard
Answer and see the solution →You are given a solid sample labelled 'unknown.' It could be one of the following: magnesium sulfate, sodium carbonate, or potassium chloride.
(a)[2 marks]Describe how you would carry out a chemical test to determine whether this solid contains carbonate ions. Include the reagents and apparatus you would use.
(b)[1 mark]Suppose the unknown is sodium carbonate. Write the ionic equation for its reaction with hydrochloric acid.
(c)[2 marks]Explain how you would confirm that the gas produced in the reaction is carbon dioxide.
Question 3
2 marks · Hard
Answer and see the solution →A solution of potassium carbonate is added to excess dilute nitric acid in a test tube. The student's teacher tells them to test any gas produced with limewater. Explain why limewater is used in this test and state the result that shows carbonate ions were present.