Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

What is an essential characteristic of an alcohol?

1. Presence of a carbon-carbon triple bond

2. Presence of a hydroxyl functional group (-OH)

3. Presence of a carbon ring structure

4. Presence of at least one carbon-carbon double bond

The correct answer is: Presence of a hydroxyl functional group (-OH)

The essential characteristic of an alcohol is the presence of a hydroxyl functional group (-OH). This functional group is what defines alcohols and differentiates them from other organic compounds. The hydroxyl group is attached to a carbon atom, and its presence is responsible for the unique properties of alcohols, such as their ability to form hydrogen bonds, which influences their physical and chemical behavior. Alcohols can vary in structure, meaning they can be found in linear, branched, or even cyclic molecules, but the defining feature will always be that hydroxyl group. Other organic compounds may have various functional groups, but the -OH group is specifically characteristic of alcohols, contributing to their classification and reactivity in chemical reactions.