Learning focus
Develop accurate organic nomenclature, connect functional groups to reactions, draw structural and polymer formulae, interpret industrial processes and apply evidence to unfamiliar compounds.
Feedstock comparison
Fermentation can use renewable glucose from crops, while hydration usually uses ethene from finite petroleum. Crop production, however, uses land, water and agricultural energy.
Operating conditions
Fermentation occurs at 25-35 C and low pressure but is slow and batch-based. Hydration uses 300 C and 6000 kPa, demanding more energy and stronger equipment, but it is fast and continuous.
Product and purification
Fermentation gives dilute ethanol and requires distillation. Hydration can produce a purer stream, although the reversible reaction needs separation and recycling.
Evaluating a method
No method is simply “better” in every context. A conclusion should state the criterion: renewable feedstock, energy cost, production rate, purity, land use or capital cost.
High-value recall and connections
Essential recall: Which method uses a renewable raw material? Fermentation, when glucose crops are sustainably grown. Which is continuous and fast? Hydration of ethene. Which gives dilute ethanol? Fermentation. Practical connection: Construct a decision table for a country with abundant crops but expensive energy, and another with a large petrochemical industry. Examination connection: Comparisons need paired statements using the same criterion.
Practical or data skill
Construct a decision table for a country with abundant crops but expensive energy, and another with a large petrochemical industry.
Examination tip
Comparisons need paired statements using the same criterion.
Review questions and suggested answers
Question 1
Which method uses a renewable raw material?
Suggested answer
Fermentation, when glucose crops are sustainably grown.
Question 2
Which is continuous and fast?
Suggested answer
Hydration of ethene.
Question 3
Which gives dilute ethanol?
Suggested answer
Fermentation.
