Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Alkenes
106 practice questions
Topics covered
Practice questions
1–10 of 44 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State the general formula for alkenes. Draw the displayed formula of propene.
Question 2
4 marks · Normal
Answer and see the solution →Alkenes are described as unsaturated hydrocarbons.
(a)[2 marks]Explain what is meant by 'unsaturated' in relation to alkenes.
(b)[2 marks]State how alkenes differ in structure from alkanes.
Question 3
3 marks · Normal
Answer and see the solution →A straight-chain alkene contains 7 carbon atoms. Calculate:
(a)[1 mark]Write the molecular formula of this alkene.
(b)[2 marks]Calculate the total number of hydrogen atoms in 5 molecules of this alkene.
Question 4
3 marks · Normal
Answer and see the solution →An unknown hydrocarbon has the molecular formula C3H6.
Explain why this compound must be an alkene rather than an alkane.
Question 5
4 marks · Normal
Answer and see the solution →The table below shows the number of carbon and hydrogen atoms in three different hydrocarbons.
Hydrocarbon Data Compound Number of carbon atoms Number of hydrogen atoms W 4 10 X 5 12 Y 6 12 (a)[2 marks]Which compound(s) could be an alkene? Explain your answer using the general formula.
(b)[2 marks]For any one compound that is not an alkene, state what structural feature it likely has instead.
Question 6
1 mark · Normal
Answer and check →Which of the following is a possible isomer of butene (C4H8)?
- A.CH3CH2CH=CH2
- B.CH3CH=CHCH3
- C.CH2=C(CH3)2
- D.All of the above
Question 7
2 marks · Normal
Answer and see the solution →Draw the displayed formula of ethene. Name the type of bond that makes ethene an unsaturated hydrocarbon.
Question 8
4 marks · Normal
Answer and see the solution →Alkenes are described as unsaturated because of a feature of their structure.
(a)[2 marks]Describe the bonding in an unsaturated hydrocarbon.
(b)[2 marks]Explain how a C=C bond affects the reactivity of alkenes compared to alkanes.
Question 9
2 marks · Normal
Answer and see the solution →State the general formula for alkenes. Write the molecular formula for the alkene with six carbon atoms.
Question 10
4 marks · Normal
Answer and see the solution →Ethene, propene and butene are alkenes.
(a)[3 marks]Complete the table to show the number of carbon (C) and hydrogen (H) atoms in each alkene.
Alkene Number of C atoms Number of H atoms Ethene 2 Propene Butene (b)[1 mark]State the physical state (solid, liquid or gas) of these alkenes at room temperature.