Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Ammonia, NH3 / The test for ammonia gas
20 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →A colourless liquid is suspected to contain water, but may also have dissolved salts. You are given a thermometer and a Bunsen burner. State how you would use these to test for the purity of the water and describe what result confirms that it is pure.
Question 2
5 marks · Hard
Answer and see the solution →A student is given three unknown gases: Gas A, Gas B, and Gas C. She is told that one may be ammonia, another is hydrogen, and the third is chlorine. She uses damp red litmus paper to test each gas.
(a)[1 mark]State what is observed when damp red litmus paper is placed in ammonia gas.
(b)[1 mark]Describe what happens to damp red litmus paper when it is exposed to chlorine gas.
(c)[2 marks]Explain why ammonia is the only alkaline gas among the three.
(d)[1 mark]Suggest an additional chemical test to identify hydrogen, apart from using litmus paper. State what result confirms hydrogen is present.
Question 3
2 marks · Hard
Answer and see the solution →A student performs a test for water using anhydrous copper(II) sulfate. The white powder turns blue when a sample liquid is added. State what this test does and does not show about the sample.