Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Chemical Tests
68 practice questions
Topics covered
Practice questions
11–20 of 31 · Normal
Question 11
4 marks · Normal
Answer and see the solution →A student is testing three white powders (A, B and C) for carbonate ions using dilute hydrochloric acid and limewater. Their results are shown:
Student's results for carbonate test Powder Acid added Fizzing observed? Limewater turns cloudy? A Yes Yes Yes B Yes No No C Yes Yes No (a)[2 marks]Which powder(s) definitely contain carbonate ions? Explain your answer.
(b)[2 marks]Suggest a reason why powder C showed fizzing but did not turn limewater cloudy.
Question 12
1 mark · Normal
Answer and check →Which observation indicates the presence of carbonate ions when dilute hydrochloric acid is added to a solid sample?
- A.The sample turns blue
- B.A green precipitate forms
- C.Effervescence (bubbles of gas) occurs
- D.The temperature falls
Question 13
2 marks · Normal
Answer and see the solution →Complete these sentences about the test for carbonate ions. (1) When dilute acid is added to a carbonate compound, __________ is given off. (2) This gas can be tested using __________.
Question 14
4 marks · Normal
Answer and see the solution →A teacher places a small amount of white powder in a test tube and adds dilute nitric acid. Bubbles appear. To confirm the identity of the gas, another experiment is performed with limewater.
(a)[1 mark]Write the formula for the ion being tested.
(b)[1 mark]State the name and formula of the gas formed.
(c)[1 mark]Describe the chemical test for this gas.
(d)[1 mark]State the positive result for this test.
Question 15
2 marks · Normal
Answer and see the solution →Describe how you would test a solid sample to show that it contains carbonate ions (). State what you would observe if carbonate ions are present.
Question 16
2 marks · Normal
Answer and see the solution →State the substance you would add to a sample to test for carbonate ions, and describe what you would observe if carbonate ions are present.
Question 17
4 marks · Normal
Answer and see the solution →A student is given a white powder thought to contain carbonate ions.
(a)[1 mark]The student adds dilute hydrochloric acid to the powder.
State what the student should observe if carbonate ions are present.
(b)[1 mark]The student collects the gas given off and bubbles it through limewater. What result would confirm the gas is carbon dioxide?
(c)[2 marks]Write the ionic equation for the reaction between carbonate ions and hydrochloric acid.
Question 18
3 marks · Normal
Answer and see the solution →A student tests 0.30 g of potassium carbonate ([K\ce{K2CO3}) powder with excess dilute hydrochloric acid. All of the carbonate reacts.
(a)[1 mark]Write the chemical equation, including state symbols, for the reaction between potassium carbonate and hydrochloric acid.
(b)[1 mark]Calculate the number of moles of potassium carbonate in 0.30 g. (Relative formula mass, , of \ce{K2CO3} = 138.0.)
(c)[1 mark]Calculate the volume of carbon dioxide gas produced at room temperature and pressure (RTP), in cm. (1 mole of gas at RTP occupies 24 000 cm.)
Question 19
2 marks · Normal
Answer and see the solution →Describe the steps you would take to test a solution for the presence of chloride, bromide, and iodide ions using silver nitrate.
Question 20
4 marks · Normal
Answer and see the solution →(a)[1 mark]State the expected observation if chloride ions are present when silver nitrate solution is added after acidifying.
(b)[1 mark]State the expected observation if bromide ions are present when silver nitrate solution is added after acidifying.
(c)[1 mark]State the expected observation if iodide ions are present when silver nitrate solution is added after acidifying.
(d)[1 mark]A student tested a solution using dilute nitric acid and silver nitrate. The result was a cream precipitate. Which ion is present?