Alcohols
Build confidence in Alcohols for GCSE Chemistry with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. A separate (triple) chemistry topic: the alcohols share the –OH group, burn in air, react with sodium and can be oxidised to carboxylic acids.
Free downloads
These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Alcohols contain the functional group –OH, and their names end in -ol. This is a Triple-only topic.
The first four are methanol, ethanol, propanol and butanol. They form a homologous series, so they share similar chemical properties that change gradually along the series.
They have four characteristic reactions and properties: they dissolve in water to form a neutral solution; they react with sodium to produce hydrogen; they burn in air; and they are oxidised by microbial action or oxidising agents to form carboxylic acids. Ethanol is produced industrially by fermentation of sugar solution using yeast at around 30 °C in anaerobic conditions.
Revision notes
Structure and naming
Alcohols contain the functional group –OH, and their names end in -ol.
The first four are methanol, ethanol, propanol and butanol, with 1, 2, 3 and 4 carbon atoms. Ethanol is C₂H₅OH.
Properties and reactions
They dissolve in water to form a neutral solution. They react with sodium to produce hydrogen.
They burn in air, releasing energy. They are oxidised by microbial action or by oxidising agents to form carboxylic acids — ethanol oxidises to ethanoic acid, which is what turns wine into vinegar.
Production and uses
Ethanol is produced by fermentation: sugar solution with yeast, at about 30 °C, in anaerobic conditions.
Alcohols are used as fuels, as solvents, and ethanol is the alcohol in alcoholic drinks.
Key points
- Alcohols contain the –OH functional group.
- Their names end in -ol.
- The first four are methanol, ethanol, propanol and butanol.
- They dissolve to form neutral solutions.
- They react with sodium to produce hydrogen.
- Ethanol is made by fermentation using yeast.
Worked examples
Example 1
Name the functional group present in all alcohols. [1 mark]
Model answer
The –OH group, also called the hydroxyl group (1 mark).
Example 2
Describe the conditions needed for fermentation to produce ethanol. [3 marks]
Model answer
A sugar solution is used with yeast (1 mark), at a temperature of around 30 °C (1 mark), in anaerobic conditions with no oxygen present (1 mark).
Example 3
Explain what happens when ethanol is oxidised. [2 marks]
Model answer
Ethanol is oxidised to form ethanoic acid (1 mark), which is a carboxylic acid and is what causes wine to turn into vinegar (1 mark).
Common mistakes
Saying alcohol solutions are alkaline.
They dissolve to form NEUTRAL solutions.
Forgetting the anaerobic condition for fermentation.
Yeast must respire anaerobically to produce ethanol.
Giving the wrong oxidation product.
Ethanol oxidises to ethanoic acid, a carboxylic acid.
Naming the functional group as OH⁻.
It is the –OH group, not the hydroxide ion.
Exam tips
- Learn the four properties and reactions as a set.
- Give all three fermentation conditions.
- Say –OH, not hydroxide ion.
- Remember this is a Triple-only topic.
Key terms
- Alcohol
- A compound containing the –OH functional group.
- Fermentation
- Producing ethanol from sugar using yeast anaerobically.
- Oxidation
- The reaction converting an alcohol to a carboxylic acid.
- Homologous series
- A family of compounds with the same functional group.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.