Alcohols are an entire family of organic compounds. Any molecule that contains the alcohol functional group is a type of alcohol.

Alcohol Functional Group:

(What is “R” ??)

Naming Alcohol Molecules

• Use prefixes to indicate the number of carbon atoms.
• Alcohols end with “-anol.”

Example:

  is butanol.

(4 carbons = “but-” prefix, then add “-anol” ending)

Physical Properties of Alcohols

• Has hydrogen bonding – these are strong intermolecular forces, but not as strong as the H-bonds in water.
• H-bonds lead to higher boiling points than similar sized alkanes
• H-bonds cause alcohols to be polar solvents
• Can also dissolve in non-polar solvents
• Less polar / weaker H-bonds if the carbon chain is longer
• Less polar / weaker H-bonds if the C-OH group is in the middle of the molecule

Chemical Properties of Alcohols

• Can be oxidized to form aldehydes and carboxylic acids. This is what happens when ethanol from alcoholic beverages is metabolized in liver cells.
• Can be oxidized (burned) all the way to CO₂, such as when ethanol is burned as a component of gasoline. Alcohols produce more water and less energy than alkanes when they burn.
• Can react to form other types of organic molecules, including esters and alkenes.

Important Alcohol Molecules

Ethanol is in alcoholic beverages and some gasoline blends. It has many other uses as well, including as a disinfectant / sanitizer and as a solvent for flavorings and medical drugs.

Rubbing alcohol is propanol:

Antifreeze contains ethylene glycol, a molecule with two alcohol functional groups:

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