Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Alkenes
106 practice questions
Topics covered
Practice questions
101–106 of 106
Question 101
6 marks · Normal
Answer and see the solution →(a)[2 marks]Combust ethene in air. Write the balanced symbol equation for this reaction.
(b)[2 marks]Describe in detail how you would use bromine water to distinguish between ethene and ethane.
(c)[2 marks]Explain why only one of these gases decolourises bromine water.
Question 102
6 marks · Normal
Answer and see the solution →(a)[2 marks]A student finds that a colourless, flammable liquid decolourises bromine water and burns with a smoky flame.
Explain what these two observations tell you about the type of hydrocarbon present.
(b)[2 marks]The student tests another liquid and observes that it does not decolourise bromine water and burns with a clean flame.
What type of hydrocarbon is this? Explain your reasoning.
(c)[2 marks]Write the displayed formula for but-1-ene, the alkene that would show these observations.
Question 103
6 marks · Normal
Answer and see the solution →Hex-2-ene, C6H12, is a liquid alkene. A sample is tested and burned under different conditions.
(a)[1 mark]State what is meant by an 'addition reaction' in the context of alkenes.
(b)[2 marks]Write a balanced chemical equation for the complete combustion of hex-2-ene, C6H12.
(c)[1 mark]Draw the structural formula of the compound formed when hex-2-ene reacts with bromine.
(d)[2 marks]Describe how you would test a sample of hex-2-ene using bromine water, and state the expected observation.
Question 104
7 marks · Hard
Answer and see the solution →This question is about alkenes and their addition reactions.
(a)[2 marks]Explain what is meant by an 'unsaturated hydrocarbon'. Refer to the bonding in your answer.
(b)[2 marks]Ethene reacts with hydrogen gas in the presence of a catalyst. Write a balanced chemical equation for this reaction using molecular formulae.
(c)[3 marks]Hydration is another important addition reaction of ethene. State the name and molecular formula of the organic product formed when ethene reacts with steam. Write a balanced chemical equation for this reaction.
Question 105
7 marks · Hard
Answer and see the solution →This question is about isomerism in alkenes and addition reactions.
(a)[2 marks]Butene (C4H8) has several isomers. Draw and name two different structural isomers of butene (use displayed formulae).
(b)[2 marks]But-1-ene reacts with hydrogen in an addition reaction. Write a balanced chemical equation for this reaction using molecular formulae.
(c)[3 marks]State the name and structural formula of the organic compound formed when but-2-ene reacts with steam.
Question 106
7 marks · Hard
Answer and see the solution →This question is about drawing and naming alkenes and their reactions.
(a)[2 marks]Draw the displayed formula of propene (C3H6). Name the type of bond responsible for its unsaturation.
(b)[2 marks]State the product and write the balanced chemical equation for the reaction between propene and hydrogen gas.
(c)[3 marks]Name the organic product and give its molecular formula when propene reacts with steam in the presence of a catalyst.