Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Alkenes
106 practice questions
Topics covered
Practice questions
21–30 of 44 · Easy
Question 21
3 marks · Easy
Answer and see the solution →Reactions of Different Alkenes Alkene Number of Carbon Atoms Number of Hydrogen Atoms Can undergo addition reaction? (Yes/No) Butene 4 8 Yes Hexene 6 12 Yes Nonene 9 18 Yes (a)[1 mark]Based on the table, state the general relationship between the number of carbon and hydrogen atoms in these alkenes.
(b)[1 mark]Explain why all three alkenes shown can undergo addition reactions.
(c)[1 mark]Predict the number of hydrogen atoms in a molecule of pentene.
Question 22
1 mark · Easy
Answer and see the solution →State the main type of bond found between carbon atoms in alkenes.
Question 23
3 marks · Easy
Answer and see the solution →(a)[1 mark]Describe what happens to the double bond in an alkene during an addition reaction.
(b)[1 mark]Name one substance that can react with an alkene in an addition reaction.
(c)[1 mark]State one product formed when ethene reacts with steam in an addition reaction.
Question 24
2 marks · Easy
Answer and see the solution →A molecule of heptene contains 14 hydrogen atoms. Calculate the number of carbon atoms in a molecule of heptene. Show your working.
Question 25
1 mark · Easy
Answer and see the solution →State the colour change observed when bromine water reacts with ethene.
Question 26
3 marks · Easy
Answer and see the solution →A student tests samples of pentane and pent-1-ene with bromine water.
(a)[1 mark]State what is observed when bromine water is added to pent-1-ene.
(b)[1 mark]State what is observed when bromine water is added to pentane.
(c)[1 mark]Explain why these observations allow you to distinguish between pentane and pent-1-ene.
Question 27
2 marks · Easy
Answer and see the solution →Write the balanced chemical equation for the addition reaction between propene ( ) and bromine ( ). State the name of the organic product formed.
Question 28
2 marks · Easy
Answer and see the solution →A student tests an unknown hydrocarbon with bromine water. The liquid does not decolourise bromine water. Explain what this result tells you about the type of hydrocarbon and give a reason.
Question 29
3 marks · Easy
Answer and see the solution →A student compares the reaction of different alkenes with bromine water. The results are shown in the table.
Alkene tested Observation with bromine water ethene colourless propene colourless but-1-ene colourless (a)[1 mark]Describe the pattern in the results.
(b)[1 mark]State a conclusion about the reaction between alkenes and bromine water.
(c)[1 mark]Suggest what would happen if pent-1-ene was tested with bromine water.
Question 30
1 mark · Easy
Answer and see the solution →What is the chemical test used to distinguish between an alkane and an alkene?