Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
111–120 of 785
Question 111
2 marks · Hard
Answer and see the solution →A hydrocarbon molecule is named 4-methylhexane.
Determine from which end of the main chain numbering should start to give the position of the methyl side chain, and explain your choice.
Question 112
5 marks · Hard
Answer and see the solution →The following hydrocarbon is shown using its skeletal formula:
Skeletal formula of a branched alkane. (a)[1 mark]State the length (number of carbon atoms) in the longest chain of the molecule.
(b)[2 marks]Name the side chain and state the carbon atom number on which it is attached.
(c)[2 marks]Write the complete IUPAC name for this molecule.
Question 113
2 marks · Hard
Answer and see the solution →Give the coding (name) for each of the following side chains found in organic molecules:
Side chain structural formula Code (name) \ce{CH_3}- \ce{CH_3CH_2}- Question 114
1 mark · Easy
Answer and see the solution →State what structural isomers have in common.
Question 115
3 marks · Easy
Answer and see the solution →(a)[1 mark]State the difference between a straight-chain alkane and a branched-chain alkane.
(b)[2 marks]Draw the displayed formula for a branched structural isomer of C5H12.
Question 116
2 marks · Easy
Answer and see the solution →Propane (C3H8) has no structural isomers. Predict and state the number of structural isomers for butane (C4H10).
Question 117
2 marks · Easy
Answer and see the solution →Explain why it is not possible to convert one structural isomer of pentane directly into another simply by rotating bonds.
Question 118
3 marks · Easy
Answer and see the solution →The table shows the number of isomers for selected alkanes.
Alkane Molecular formula Number of isomers Methane CH4 1 Ethane C2H6 1 Propane C3H8 1 Pentane C5H12 3 (a)[1 mark]Describe the trend in the number of isomers as the number of carbon atoms increases.
(b)[2 marks]Suggest why methane, ethane, and propane each have only one isomer.
Question 119
1 mark · Easy
Answer and see the solution →Give the molecular formula for the straight-chain alkane with five carbon atoms.
Question 120
3 marks · Easy
Answer and see the solution →(a)[1 mark]State the molecular formula for hexane.
(b)[2 marks]Explain what makes two different hexane molecules structural isomers.