GCSE Chemistry revision

Alcohols

Reactions of alkenes and alcohols (chemistry only)

AQA 4.7.2.3 Foundation & Higher

Your specification

AQA student objectives

Learning pathway

ALL 🎯

MOST 🎯🎯

SOME 🎯🎯🎯

Revision summary

Read on screen, then print for Cornell-style active revision.

Alcohols are a homologous series of organic compounds, similar to alkanes but with an –OH (hydroxyl) functional group replacing one hydrogen atom.
The naming of alcohols follows the same pattern as alkanes, but the final '-e' is replaced with '-ol' (e.g., ethane becomes ethanol).
The general formula for alcohols is CₙH₂ₙ₊₁OH, and the –OH group should always be written at the end of the molecular formula.

1. What Are Alcohols? AQA

Alcohols are a homologous series of organic compounds, similar to alkanes but with an –OH (hydroxyl) functional group replacing one hydrogen atom.
The naming of alcohols follows the same pattern as alkanes, but the final '-e' is replaced with '-ol' (e.g., ethane becomes ethanol).
The general formula for alcohols is CₙH₂ₙ₊₁OH, and the –OH group should always be written at the end of the molecular formula.

You need to know the first four alcohols in the homologous series: methanol, ethanol, propanol, and butanol.
Each successive alcohol in the series has one more carbon atom and two more hydrogen atoms than the previous one.
As the molecules get larger along the homologous series, certain physical properties (such as boiling point) change gradually.

2. The First Four Alcohols AQA

You need to know the first four alcohols in the homologous series: methanol, ethanol, propanol, and butanol.
Each successive alcohol in the series has one more carbon atom and two more hydrogen atoms than the previous one.
As the molecules get larger along the homologous series, certain physical properties (such as boiling point) change gradually.

Alcohols are flammable, meaning they undergo complete combustion in air, reacting with oxygen to produce carbon dioxide and water.
A combustion equation for ethanol can be written as: C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O, balanced like any other equation.
Alcohols are soluble in water, dissolving to form a neutral solution (neither acidic nor alkaline).
Alcohols can be oxidised to form carboxylic acids; for example, ethanol gains an

3. Properties of Alcohols AQA

Alcohols are flammable, meaning they undergo complete combustion in air, reacting with oxygen to produce carbon dioxide and water.
A combustion equation for ethanol can be written as: C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O, balanced like any other equation.
Alcohols are soluble in water, dissolving to form a neutral solution (neither acidic nor alkaline).
Alcohols can be oxidised to form carboxylic acids; for example, ethanol gains an

Because alcohols are flammable and release energy during combustion, they can be used as fuels — spirit burners in school labs burn ethanol for this reason.
Alcohols are widely used as solvents in industry because they can dissolve substances that water cannot, such as hydrocarbons and lipid compounds like fats and oils.
The ability of alcohols to mix with both water-soluble and non-water-soluble substances makes them especially versatile as industrial solvents.

4. Uses of Alcohols AQA

Because alcohols are flammable and release energy during combustion, they can be used as fuels — spirit burners in school labs burn ethanol for this reason.
Alcohols are widely used as solvents in industry because they can dissolve substances that water cannot, such as hydrocarbons and lipid compounds like fats and oils.
The ability of alcohols to mix with both water-soluble and non-water-soluble substances makes them especially versatile as industrial solvents.