13147 17 There are five aliphatic structural isomers with molecular formula C5H10. (a) Define the term structural isomers. [1] (b) Two of the aliphatic structural isomers are described as having unbranched structures and three are described as branched. Complete the table below for the five aliphatic structural isomers of C5H10. IUPAC name of isomer Skeletal formula 2-methylbut-1-ene [5] 13147 [Turn over (c) The molecule on the left below does not exist as E–Z isomers whereas the molecule on the right does. Draw the Z isomer of the molecule on the right and explain, in terms of priority, why the structure is classified as the Z isomer. Explain why the molecule on the left does not exist as E–Z isomers whereas the molecule on the right does. In this question you will be assessed on using your written communication skills including the use of specialist scientific terms. Z isomer: [6]