This exam tips covers Exam Tips: Alcohols within Alcohols for GCSE Chemistry. Revise Alcohols in Organic Chemistry for GCSE Chemistry with 20 exam-style questions and 15 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 12 of 13 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 12 of 13
Practice
20 questions
Recall
15 flashcards
💡 Exam Tips: Alcohols
🎯 Common Question Types:
- Write the fermentation equation for ethanol (2 marks)
- Compare fermentation and hydration of ethene (4 marks)
- State the functional group of alcohols (1 mark)
- Explain why ethanol dissolves in water (2 marks)
📝 Key Command Words:
- Write: Balanced equation with CO₂ product for fermentation
- Compare: State difference for each aspect (not just describe one)
- Explain: Hydrogen bonding with water for solubility
⚠️ Common Mistakes to Avoid:
- Forgetting CO₂ in the fermentation equation
- Saying fermentation requires oxygen (it's anaerobic)
- Writing the functional group as "OH" without the dash (-OH)
Quick Check: Write the word equation and symbol equation for the fermentation of glucose.
Word equation: glucose → ethanol + carbon dioxide (using yeast enzymes, anaerobic, 25-35°C). Symbol equation: C₆H₁₂O₆(aq) → 2C₂H₅OH(aq) + 2CO₂(g).
Quick Check: Give one advantage and one disadvantage of producing ethanol by fermentation compared to hydration of ethene.
Advantage: Fermentation uses renewable resources (plant sugars), so it is more sustainable and approximately carbon neutral. Disadvantage: Fermentation is much slower than hydration of ethene and produces impure ethanol that requires distillation.