Form ethyl ethanoate from ethanol and an acyl chloride
React ethanol with ethanoyl chloride to form the ester ethyl ethanoate and hydrogen chloride.
Section 32 · Hydroxy compounds
A Level; Cambridge International Chemistry 9701, 2028–2030 syllabus, Topic 32. Distinguish phenol (–OH directly on an aromatic ring) from an alcohol (–OH on an aliphatic carbon). Use the specified reagents, temperatures and products; phenol reactions are limited to those listed in the syllabus. Written practice is self-checked
Before you begin
- Recognise alcohols and phenols, aromatic substitution, acids and bases, and diazonium ions from the preceding organic topics.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What ester forms when ethanol reacts with ethanoyl chloride?
What you will learn
- Recall the esterification reaction of an alcohol with an acyl chloride
- Identify ethanol and ethanoyl chloride as the syllabus example
- Write ethyl ethanoate and HCl as products
An alcohol reacts with an acyl chloride
Ethanol reacts with ethanoyl chloride to form ethyl ethanoate and hydrogen chloride. The alcohol contributes the oxygen in the ester linkage; the acyl chloride contributes the ethanoyl group.
The product contains the ester linkage –COO–. Keep the ethyl part from ethanol and the ethanoate part from ethanoyl chloride when naming ethyl ethanoate.
Track the atoms in the equation
CH₃COCl + CH₃CH₂OH → CH₃COOCH₂CH₃ + HCl. The chlorine leaves as chloride and combines with the hydrogen from the alcohol O–H group to form HCl overall.
This is nucleophilic addition–elimination at the acyl chloride carbonyl, already introduced in Topic 29. The syllabus outcome here asks you to describe ester formation using ethyl ethanoate as the example.
Pause and explain
Which by-product forms alongside ethyl ethanoate?
Worked example
Name the ester formed from ethanol and ethanoyl chloride.
Show the worked solution
- The alcohol supplies the ethyl group.
- The acyl part is ethanoate from ethanoyl chloride.
- The ester name places the alkyl part first.
Answer Ethyl ethanoate forms, together with HCl.
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Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Complete the products: CH₃COCl + CH₃CH₂OH → ?
Give me a hint
Combine the ethanoyl group with ethanol's oxygen and ethyl group.
Compare my reasoning
- The ester linkage is –COO–.
- Keep the two-carbon ethyl fragment.
- Account for the removed H and Cl as HCl.
CH₃COOCH₂CH₃ + HCl (ethyl ethanoate and hydrogen chloride).
Look for these in your work
- Ester structure correct
- Ethyl group retained
- By-product accounted
Explain why the ester is called ethyl ethanoate.
Give me a hint
Identify which reactant contributes each named part.
Compare my reasoning
- Ethanol contributes the ethyl group.
- Ethanoyl chloride contributes the ethanoate acyl part.
- Name the alkyl part before the carboxylate part.
It is ethyl ethanoate because the ester has an ethyl group from ethanol and an ethanoate part from ethanoyl chloride.
Look for these in your work
- Alcohol-derived part identified
- Acyl-derived part identified
- Name assembled correctly
A student names the product methyl ethanoate. What structural check reveals the error?
Give me a hint
Count carbons in the alcohol-derived alkyl group.
Compare my reasoning
- Ethanol has two carbon atoms.
- The group attached through ester oxygen is CH₃CH₂–.
- That is ethyl, not methyl.
The alcohol is ethanol, so the ester contains an ethyl group and is ethyl ethanoate, not methyl ethanoate.
Look for these in your work
- Alcohol carbon count checked
- Attached group identified
- Name corrected
Common mistakes
- Naming the product ethanoic acid
- Dropping one carbon from the ethyl group
- Forgetting HCl is a by-product
- Confusing esterification with oxidation of ethanol
What can you explain now?
What ester forms when ethanol reacts with ethanoyl chloride?
Compare with the explanation
Ethyl ethanoate
The alcohol contributes ethyl and the acyl chloride contributes ethanoate.
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Make it stick
How do the alcohol and acyl chloride contribute to the name and structure of ethyl ethanoate?
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