Properties of alcohols

General formula

Cn H2n+1 OH

Nomenclature

• - Ol at the end

• 2 hydroxyl groups = diol

• 3 hydroxyl groups = triol

Primary alcohol

• 1º

• - OH is attached to a carbon with one alkyl group attached

Secondary alcohol

• 2º

• - OH group is attached to a carbon with 2 alkyl groups attached

Tertiary alcohol

• 3°

• -OH group is attached to a carbon with 3 alkyl groups attached

Physical properties of alcohols

• Polar → has electronegative hydroxyl group (pulls electrons in c-oh bond away from carbon atom )

• -OH group is also polar → has δ- on oxygen δ+ on hydrogen = hydrogen bonds can form

• Low volatility due to hydrogen bonds (strong intermolecular forms) so they don't evaporate easily into gas

Trend in hydrogen bonding

Small alcohols → hydrogen bonding allows for solubility in water

Larger alcohol → most of molecule is non-polar = decreased solubility in water