Naming organic compounds
2 marks · EasyExplain why the compound with the formula CH3CH2CH=CH2 is named but-1-ene according to IUPAC rules.
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Must show: shows 4 carbons, double bond position 1
Common mistakes: butene
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Marking points
M1 · 1 mark · States compound has 4 carbons (but-) and a double bond (–ene).
A1 · 1 mark · Explains the double bond starts at carbon 1, giving the name but-1-ene.
Worked solution
The compound has 4 carbon atoms in a straight chain, which gives the root name 'but-'.
The carbon–carbon double bond starts at the first carbon when counting from the end nearest the double bond. According to IUPAC rules, this is but-1-ene.