Given the following structure: $CH$₃-CH₂-CHO, name the aldehyde displayed below.

• A. Propanal
• B. Methanal
• C. Butanal
• D. Ethanol

Answer: (A)

Verified step by step guidance

1. Identify the functional group present in the given structure. The presence of \( \text{CHO} \) (an aldehyde group) at the end of the carbon chain indicates that the compound is an aldehyde.
2. Count the total number of carbon atoms in the longest continuous chain that includes the aldehyde group. In this case, the chain is \( \text{CH}_3 - \text{CH}_2 - \text{CHO} \), which has 3 carbon atoms.
3. Recall the naming convention for aldehydes: the suffix '-al' is added to the alkane name corresponding to the number of carbons. For 3 carbons, the alkane is propane, so the aldehyde is named propanal.
4. Compare the options given: Methanal (1 carbon), Propanal (3 carbons), Butanal (4 carbons), Ethanol (an alcohol, not an aldehyde). Since the structure has 3 carbons and an aldehyde group, the correct name is propanal.
5. Confirm that the aldehyde group is at the end of the chain, which is consistent with the aldehyde naming rules, ensuring the name propanal is appropriate.