What is the IUPAC name for a compound with the formula C5H10O?

To determine the correct IUPAC name for a compound with the formula C5H10O, it's important to recognize that this formula corresponds to a molecule that may fall into one of several functional groups, namely aldehydes, ketones, or alcohols.

The molecular formula C5H10O can represent either a ketone, in which the carbonyl group (C=O) is located within the carbon chain, or an aldehyde, where the carbonyl is at the end of the chain. In this case, the structure indicated by choosing "B" (Pentanone) identifies the compound as a ketone. Specifically, the simplest form of pentanone is 2-pentanone, which adheres to the IUPAC naming conventions where ketones are named by identifying the longest carbon chain that includes the carbonyl group, followed by the suffix '-one'.

Pentanone differs from pentanal (an aldehyde) and pentanol (an alcohol), both of which would have distinct properties based on their functional groups. Aldehydes (like pentanal) typically have a carbonyl group at the terminal position, and alcohols (like pentanol) have a hydroxyl group (-OH) that would change