Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Coding for branched chains
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →Give the coded names for the following side chains in organic molecules:
(a)[1 mark]A side chain with the formula
(b)[1 mark]A side chain with the formula
Question 2
4 marks · Normal
Answer and see the solution →The compound below has five carbon atoms in its longest chain. It is shown with numbered carbon atoms, and a side chain:
(a)[1 mark]Write the name of the longest chain.
(b)[2 marks]Structural formula of the molecule Identify the type and position of the side chain shown.
(c)[1 mark]Give the full IUPAC name of the compound.
Question 3
3 marks · Normal
Answer and see the solution →Explain how to identify a methyl side chain in the structural formula of an organic molecule. Your answer should refer to the features of methyl groups and how to recognize them.
Question 4
4 marks · Normal
Answer and see the solution →Study the following table showing the names and structures of several branched alkanes.
Branched Alkane Structures Name Longest chain Side chain(s) Position(s) 2-methylbutane butane methyl 2 3-ethylpentane pentane ethyl 3 2,2-dimethylpropane propane methyl (x2) 2,2 4-methylhexane hexane methyl 4 (a)[1 mark]Which molecule in the table has two side chains?
(b)[1 mark]State the side chain and its position for 3-ethylpentane.
(c)[1 mark]For which compound is the main chain the longest?
(d)[1 mark]What is the coded name for a side chain containing two carbon atoms?
Question 5
1 mark · Normal
Answer and check →Which of the following is the correct IUPAC name for the molecule with this structural formula?
Skeletal formula: four carbon atoms in a row, with a methyl group attached to the second carbon. - A.2-methylbutane
- B.3-methylbutane
- C.methylpropane
- D.2-ethylpropane
Question 6
2 marks · Normal
Answer and see the solution →State the coding for the following side chains used in organic nomenclature:
(a)[1 mark]A one-carbon branch
(b)[1 mark]A two-carbon branch
Question 7
4 marks · Normal
Answer and see the solution →A hydrocarbon molecule contains six carbon atoms in its longest chain and a methyl group as a side chain.
(a)[1 mark]What is the name of the six-carbon main chain?
(b)[2 marks]If the methyl group is attached to carbon atom 2 (when numbered from the end closest to the side chain), give the IUPAC name of the compound.
(c)[1 mark]Explain why it is important to number from the end of the chain closest to the side chain.
Question 8
3 marks · Normal
Answer and see the solution →The systematic name of a hydrocarbon is 3-ethyl-2-methylpentane.
State the number of carbon atoms in the longest chain, and give the total number of carbon atoms in the complete molecule.
Show your reasoning.