STUDENT SPACE · TOPIC 5

Ethanol production and uses

Compare fermentation with hydration and explain ethanol as a fuel and solvent.

The essentials

C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂. Use aqueous glucose, yeast, 25–35 °C and absence of oxygen.
C₂H₄ + H₂O → C₂H₅OH. Use steam, 300 °C, 60 atm (6000 kPa) and an acid catalyst.
Fermentation uses renewable plant material and a low temperature, but is slow and produces a dilute solution.
C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O. Complete combustion releases energy.

Try each question before opening its hint or answer. Use paper for calculations and diagrams.

Why is a flame unsuitable for heating an ethanol sample?

Need a hint for Question 1?

Compare the same feature for both routes, then link it to the producer’s need.

Check Question 1

Ethanol is flammable. Use an approved non-flame heating method.

Write the balanced fermentation equation and state its conditions.

Need a hint for Question 2?

Balance glucose forming ethanol and carbon dioxide.

Check Question 2

C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂. Aqueous glucose, yeast, 25–35 °C, no oxygen.

Give one advantage and one disadvantage of fermentation compared with hydration.

Need a hint for Question 3?

Compare the same feature of the two routes.

Check Question 3

Renewable feedstock or lower temperature. Slower batch production or dilute ethanol requiring separation.

Use Lesson 5 in your worksheet for written practice. Your teacher will discuss those answers in class.