Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
341–350 of 785
Question 341
4 marks · Normal
Answer and see the solution →The table below shows the number of carbon atoms and the molecular formula for three alkenes. For each, state if the formula is correct for an alkene. If not, explain your answer.
Alkene Number of C atoms Molecular formula W 4 C4H8 X 5 C5H12 Y 3 C3H6 Question 342
1 mark · Normal
Answer and check →Which statement about the physical properties of alkenes with 2 to 4 carbon atoms is correct?
- A.They are all gases at room temperature.
- B.They are all liquids at room temperature.
- C.Their boiling points decrease as the number of carbon atoms increases.
- D.They are solids at room temperature.
Question 343
2 marks · Normal
Answer and see the solution →State the general formula for alkenes and give the displayed formula for propene.
Question 344
4 marks · Normal
Answer and see the solution →The table below gives information about three alkenes.
Alkene Number of carbon atoms Boiling point (°C) Ethene 2 -104 Propene 3 -47 Butene 4 -6 (a)[2 marks]Describe the trend in boiling points shown in the table.
(b)[2 marks]Explain why the boiling point increases as the number of carbon atoms increases.
Question 345
2 marks · Hard
Answer and see the solution →A student claims that all alkenes have the same general formula. State this general formula and explain how it shows that alkenes are unsaturated.
Question 346
5 marks · Hard
Answer and see the solution →The physical properties of alkenes with 2 to 4 carbon atoms show a trend.
(a)[2 marks]State the physical state of ethene, propene and butene at room temperature.
(b)[2 marks]Describe how the boiling points of these alkenes change as the number of carbon atoms increases from ethene to butene.
(c)[1 mark]Explain why the trend you described in part (b) occurs.
Question 347
2 marks · Hard
Answer and see the solution →State the general formula for alkenes. Explain, using your formula, how you can determine the number of hydrogen atoms in an alkene containing 9 carbon atoms.
Question 348
1 mark · Easy
Answer and see the solution →State the general formula for alkenes.
Question 349
3 marks · Easy
Answer and see the solution →(a)[1 mark]State what is meant by an addition reaction of an alkene.
(b)[1 mark]Write the word equation for the reaction between ethene and bromine.
(c)[1 mark]What structural feature of ethene allows it to take part in addition reactions?
Question 350
2 marks · Easy
Answer and see the solution →An alkene has 15 carbon atoms in its molecule. Calculate the number of hydrogen atoms in one molecule of this alkene. Show your working.