Study Chemistry notes on Alcohols for A-Level. Useful for revision, homework, and exam preparation in Zimbabwe.
A free account is needed to download. Sign in or create one
This is the A-Level Chemistry notes. It is a free notes for revision.
1
HAMILTON HIGH SCHOOL SCIENCE DEPARTMENT
"ORGANIC CHEMISTRY - ALCOHOLS" COMPILED BY C CHAKWANA
Alcohols are saturated molecules containing an -OH group. The H atom in the $\mathrm{O}-\mathrm{H}$ bond can hydrogen bond with other alcohol molecules and with water, which is why alcohols have relatively high boiling points and many are soluble in water.
They have the general formula $\mathrm{C}_{n} \mathrm{H}_{2 \mathrm{n}+1} \mathrm{OH}$ Examples: $\mathrm{CH}_{3} \mathrm{OH}$ - methanol, $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}$ ethanol.
Alcohols may be classified into aromatic alcohols ie an alcohol group attached to a benzene ring (eg phenol is an aromatic alcohols), or they can be classified into aliphatic alcohols these have a general formula ROH where R is an alkyl group (e.g ethanol is an aliphatic alcohol.
1. Naming alcohols and phenols(nomenclature)
Alcohols as you may remember, are named by using the suffix-ol. Locants are used to indicate the carbon atom to which the -OH group is attached. Prefixes di, tri-are used to show the number of -OH - groups in a molecule.
ORGANIC CHEMISTRY BY C CHAKWANA HHS
Examples
Butan-2,3-diol
When the -OH group is not the principal functional group the name is prefixed by hydroxy. Phenols are named as derivatives of benzene to which the -OH group is attached directly. If the -OH is not the main functional group the prefix hydroxy is used as in alcohols.