Drawing and naming the carboxylic acids
2 marks · HardA student writes the name 'proponoic acid' for a carboxylic acid with three carbon atoms in a straight chain.
State the correct IUPAC name for this acid. Give one reason for your answer.
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Also accept: propanoic acid and a suitable explanation (e.g. 'because the three-carbon chain is named "prop" and carboxylic acids end in -anoic acid')
Common mistakes: proponoic acid; propenoic acid; giving a formula instead of a name
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Marking points
A1 · 1 mark · Correct IUPAC name: propanoic acid
E1 · 1 mark · Valid reason: It's based on a three-carbon unbranched chain, so 'prop' prefix; ends '-anoic acid' for carboxylic acids.
Worked solution
The correct name is propanoic acid. The prefix 'prop' indicates a three-carbon chain, and '-anoic acid' denotes an unbranched carboxylic acid.