Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Ammonia, NH3 / The test for ammonia gas
20 practice questions
Practice questions
1–8 of 8 · Easy
Question 1
1 mark · Easy
Answer and see the solution →State the colour change observed when ammonia gas is tested with damp red litmus paper.
Question 2
3 marks · Easy
Answer and see the solution →(a)[1 mark]Describe how anhydrous copper(II) sulfate can be used to test an unknown liquid for water.
(b)[1 mark]State the colour change you would see if water is present.
(c)[1 mark]Explain if this test indicates whether the water is pure.
Question 3
2 marks · Easy
Answer and see the solution →Explain why measuring the boiling point of a liquid is used to test the purity of water. What result should you obtain if the water sample is pure?
Question 4
3 marks · Easy
Answer and see the solution →A student tested three samples of gas (A, B, and C) using damp red litmus paper. Their results are recorded in the table below.
Results of gas tests using damp red litmus paper Sample Observation A Red litmus paper turns blue B No change C Red litmus paper turns white (a)[1 mark]Identify the sample that contains ammonia.
(b)[1 mark]Give a reason for your answer to part (a).
(c)[1 mark]Suggest the gas that could be present in sample C.
Question 5
1 mark · Easy
Answer and see the solution →State the melting (freezing) point of pure water at 1 atmosphere pressure.
Question 6
3 marks · Easy
Answer and see the solution →(a)[2 marks]Describe the steps for testing a sample for ammonia gas using litmus paper.
(b)[1 mark]Explain why the litmus paper must be damp.
Question 7
2 marks · Easy
Answer and see the solution →A water sample was tested and its boiling point found to be 101.5°C at 1 atmosphere pressure. Calculate by how much the boiling point differs from that of pure water. Is the sample likely to be pure?
Question 8
2 marks · Easy
Answer and see the solution →A student carries out a test for ammonia gas using damp red litmus paper. The student expects to see the colour of the paper change. If the student starts with 5 pieces of damp red litmus paper and plans one test for each of 5 gas samples, how many pieces of red litmus paper will change colour if all 5 samples are ammonia gas? State the final colour of the litmus paper.