Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Chemical Tests
68 practice questions
Topics covered
Practice questions
11–20 of 28 · Easy
Question 11
3 marks · Easy
Answer and see the solution →Test results for carbonate ions. Sample Dilute acid added Fizzing observed Gas turns limewater cloudy X Yes Yes Yes Y Yes No - Z Yes Yes No (a)[1 mark]Which sample(s) most likely contain carbonate ions? Explain your answer.
(b)[1 mark]Suggest a possible identity for the gas produced from sample Z.
(c)[1 mark]Explain why sample Y does not give the same results as X.
Question 12
1 mark · Easy
Answer and see the solution →Write the ionic equation for the reaction between a carbonate ion and an acid.
Question 13
3 marks · Easy
Answer and see the solution →(a)[2 marks]A teacher gives you a sample to test for carbonate ions. Describe fully how you would carry out this test.
(b)[1 mark]State how you would know if carbonate ions are present.
Question 14
2 marks · Easy
Answer and see the solution →A student tests 0.20 g of sodium carbonate powder by adding excess dilute hydrochloric acid. Calculate the maximum volume of carbon dioxide gas produced at room temperature and pressure (RTP), assuming that 1 mole of gas occupies 24 dm^3 at RTP. (Relative formula mass of Na2CO3 = 106)
Question 15
2 marks · Easy
Answer and see the solution →A powder is suspected to contain carbonate ions (CO3^2-). Describe the two steps you would take to confirm the presence of carbonate ions in the powder and explain what results would show that carbonate ions are present.
Question 16
2 marks · Easy
Answer and see the solution →A student wants to test for carbonate ions using dilute hydrochloric acid. She needs at least 0.22 g of carbon dioxide gas (CO2) to turn limewater cloudy. Calculate the minimum mass of sodium carbonate (Na2CO3) required to produce 0.22 g of CO2, assuming all of the carbonate reacts and only this gas is formed.
Relative atomic masses: Na = 23, C = 12, O = 16
Question 17
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 18
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 19
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 20
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.