An organic compound featuring a hydroxyl group attached to a hydrocarbon is called?

• A. Ether
• B. Ester
• C. Alcohol
• D. Carboxylic acid

Answer: (C)

A hydroxyl group bonded directly to a carbon in a hydrocarbon chain defines an alcohol. The -OH substituent on carbon is the giveaway, giving compounds like R-OH where the rest of the molecule is hydrocarbon.

Ethers have oxygen linking two carbon groups (R-O-R) with no -OH attached to carbon, so they aren’t alcohols. Esters feature a carbonyl (C=O) bonded to an -O- that connects to another carbon group (R-CO-O-R), not a free hydroxyl on carbon. Carboxylic acids contain a carboxyl group (-COOH), where the -OH is part of that carboxyl group attached to a carbonyl carbon, not a simple hydroxyl on a hydrocarbon chain. Because of this, the hydroxyl-bearing hydrocarbon corresponds to alcohol.