Final answer:
The IUPAC names provided are largely correct: Propanoic acid should be ethanoic acid, butanal is correct, ethoxyethane is correct, and methanoic acid is also correctly named.
Step-by-step explanation:
The question concerns the correct IUPAC naming of organic compounds. IUPAC nomenclature is a standardized system for naming chemical compounds, and it is important to apply the rules accurately for clear communication in the field of chemistry.
- Propanoic acid is correctly named ethanoic acid, as the compound contains two carbons in its longest chain, not three as 'propanoic' might suggest.
- Butanal is an aldehyde with four carbons in its longest chain and should be correctly named as butanal without any change.
- Ethoxyethane is correctly named as such under IUPAC naming conventions, often also known as diethyl ether as a common name.
- Methanoic acid is correctly named and is the simplest carboxylic acid with a single carbon atom.