A home brewer makes wine from grape juice. The grape juice contains sugars such as glucose.
The brewer adds a microorganism to the juice, then leaves it in a warm place in a container fitted with an airlock. The airlock lets gas escape but stops air getting in.
Name the microorganism that is added to the grape juice.
Bubbles of gas escape through the airlock. Name this gas.
Suggest a suitable temperature for the container.
Explain why air must be kept out of the container.
The wine contains about 12% ethanol. Name the separation technique used to produce a drink with a much higher concentration of ethanol.
The table shows the boiling points of ethanol and water.
| Substance | Boiling point / °C |
|---|---|
| ethanol | 78 |
| water | 100 |
Use the table to explain why ethanol can be separated from water by this technique.
43 exam-style questions on Edexcel GCSE Chemistry 10.4 Alcohols and carboxylic acids, covering 10.4.1 Alcohols and the -OH functional group, 10.4.2 Carboxylic acids and the -COOH functional group, 10.4.3 Oxidation of alcohols and homologous series, and 10.4.4 Fermentation and fractional distillation of ethanol. Each one has a worked solution and a mark scheme showing where the marks go.