Other important addition reactions of alkenes

3 marks · Normal

The hydration of ethene is used industrially to make ethanol from ethene and steam. Write a balanced chemical equation for this reaction. Give two reasons why converting ethene to ethanol by hydration is important for industry.

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CH2=CH2 + H2O → CH3CH2OH; Ethanol production is important because it produces high-purity ethanol efficiently and uses widely available ethene from crude oil.

Must show: Balanced chemical equation: CH2=CH2 + H2O → CH3CH2OH (or in condensed form), Two industrial reasons: e.g., produces high-purity ethanol; fast/efficient/continuous process; uses readily available raw materials; ethanol is a key industrial chemical

Also accept: Ethanol produced is used as a solvent and in fuels; Ethanol can be made on a large scale quickly

Common mistakes: Giving incomplete or unbalanced equations; Describing fermentation instead of hydration

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Marking points

M1 · 1 mark · Writes a balanced chemical equation for the hydration of ethene: CH2=CH2 + H2O → CH3CH2OH

B1 · 1 mark · States one industrial benefit (e.g., produces high-purity ethanol, fast process, continuous/efficient).

B2 · 1 mark · States a second correct reason for industrial use (e.g., uses cheap/widely available ethene, large scale, etc.).

Worked solution

Balanced equation:

Reason 1: The process produces high-purity ethanol quickly (continuous and efficient reaction).

Reason 2: Ethene is widely available from crude oil, making the raw materials cheap and plentiful for industry.