Functional group of alcohols.

**The reasoning** Alcohols are organic compounds where a hydroxyl group (—OH) is directly attached to a carbon atom. Think of common alcohols you know: ethanol (the type in drinks), methanol (in methylated spirit), propanol. They all have that —OH group bonded to a carbon chain. This —OH is what makes them alcohols and gives them their characteristic properties — like being able to dissolve in water and having those boiling points you studied. **Why the wrong options tempt you** - **—COOH** looks similar and also contains OH, but this is a *carboxylic acid* group (like in vinegar/ethanoic acid). The C=O makes it acidic, not alcoholic. - **—CHO** is an *aldehyde* group (like in methanal/formaldehyde). Yes, it has oxygen, but no OH. - **—NH₂** is an *amine* group (contains nitrogen, not the oxygen you need for alcohols). The trap? All these groups contain common elements, but each defines a completely different family of organic compounds. **Quick takeaway** **Alcohol = —OH attached to carbon.** Remember: "OH" literally sounds like alcohol's effect — "Ohh!" 😄