A company makes ethanol by fermenting glucose solution with yeast.
A student investigates how temperature affects the rate of fermentation. The student measures the volume of carbon dioxide given off in 10 minutes at different temperatures.
The table shows the results.
| Temperature / °C | Volume of carbon dioxide in 10 minutes / cm3\mathrm{cm^{3}}cm3 |
|---|---|
| 15 | 12 |
| 25 | 30 |
| 35 | 48 |
| 45 | 20 |
| 55 | 2 |
Write the balanced equation for the fermentation of glucose, C6H12O6\mathrm{C_{6}H_{12}O_{6}}C6H12O6, to form ethanol and carbon dioxide. Include state symbols.
Describe the effect of temperature on the volume of carbon dioxide produced.
The student concludes that the best temperature for fermentation is exactly 35 °C. Explain why the student cannot be certain of this, and suggest how the investigation could be improved.
Describe how the student could measure the volume of carbon dioxide given off.
Calculate the volume of carbon dioxide produced at room temperature and pressure when 0.60 mol of glucose is fermented completely. The volume of 1 mol of any gas at room temperature and pressure is 24 dm3\mathrm{dm^{3}}dm3.
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.