Method 1: Fermentation (The Ancient Way)
C₆H₁₂O₆(aq) → 2C₂H₅OH(aq) + 2CO₂(g)
glucose (with yeast) → ethanol + carbon dioxide
• Temperature: 25-35°C (room temperature)
• Yeast enzymes as biological catalyst
• Absence of oxygen (anaerobic)
• Takes days to weeks
Think of fermentation like a microscopic brewery where yeast are tiny workers. They eat sugar (glucose) and produce alcohol as waste — lucky for us! But they're living organisms, so they need the right temperature (not too hot or cold) and can't work if oxygen is around.
Method 2: Hydration of Ethene (The Industrial Way)
C₂H₄(g) + H₂O(g) → C₂H₅OH(l)
ethene + steam → ethanol
• Temperature: 300°C (high temperature)
• Pressure: 70 atmospheres
• Phosphoric acid catalyst
• Continuous process — minutes to complete
This required practical covers Production Methods for Ethanol within Alcohols for GCSE Chemistry. Revise Alcohols in Organic Chemistry for GCSE Chemistry with 22 exam-style questions and 15 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 4 of 13 in this topic. Revise both the method and the reason for each step, because practical questions often test understanding rather than pure recall.
Practice questions for Alcohols
What is the functional group present in all alcohols?
Explain what happens when ethanol reacts with sodium metal. Include a balanced equation in your answer.