Acid hydrolysis
Ethyl acetate and water react reversibly to form ethanoic acid and ethanol.
- Reagents
- Water; dilute acid catalyst
- Conditions
- Heat under reflux in aqueous acid
- Reaction class
- Acid hydrolysis
- Equation
- CH3COOCH2CH3 + H2O <=> CH3COOH + CH3CH2OH
Overview
Ethyl acetate and water react reversibly to form ethanoic acid and ethanol.
Transformation
- Equation
- CH3COOCH2CH3 + H2O <=> CH3COOH + CH3CH2OH
- Reactants
- Ethyl acetate + Water
- Products
- Ethanoic acid + Ethanol
- Reagents
- Water; dilute acid catalyst
- Environment
- Heat under reflux in aqueous acid
- Reaction class
- Acid hydrolysis
- Mechanism
- acid-catalysed ester hydrolysis
- Evidence level
- source-backed molecular example
Reference procedure
Ethyl ethanoate hydrolysis: product analysis
Ethyl ethanoate + water ⇌ ethanoic acid + ethanol
Materials and quantities
- Ethyl ethanoate
- Water and acid catalyst; choose an approved method before work
Apparatus
- Reflux arrangement for a supervised method
- Product-separation and analytical equipment
Procedure
- Identify which ester fragment becomes the alcohol and explain the reversible acid-catalysed reaction.
- Plan a comparison of starting material and final mixture rather than assuming reflux means full conversion.
Work-up and isolation
- A volatile fraction can contain ester, alcohol and water; separation needs composition evidence.
- Use complementary NMR or other measured data to support ethanol identification.
Critical controls
- Acidity alone cannot quantify ester conversion in the presence of an acid catalyst.
- Fractional distillation may improve separation, but does not by itself establish anhydrous ethanol.
Practical techniques
Reflux setup
Boil the reaction while returning condensed vapour to the same flask, so volatile material is not continuously lost.
Setup
- Charge the flask before fitting the condenser; do not fill the flask more than about half full.
- Run cooling water into the lower condenser inlet and out from the upper outlet.
- Keep the top of an ordinary reflux condenser open to the atmosphere unless the cited procedure specifies a pressure-rated closed system.
- Heat to a gentle, steady boil so the condensation line remains within the condenser and liquid returns continuously to the flask.
Operating checks
- Use an electric bath or mantle for flammable organic liquids; do not use a naked flame.
- Start condenser water before heating and confirm that hoses are secure.
- If addition is exothermic, complete the controlled addition and cooling stage before sustained reflux.
Fractional distillation
A fractionating column provides repeated condensation and evaporation, improving separation of miscible volatile liquids.
Setup
- Fit the column between the boiling flask and still head; position the thermometer in the outgoing vapour path.
- Record temperature and fraction changes during a steady, controlled distillation.
Operating checks
- A narrow boiling range is supporting evidence, not proof of complete purity.
- Ethanol and water cannot be assumed to separate into absolutely pure liquids by ordinary fractional distillation.
NMR structure and mixture checks
Relate nuclear environments to a candidate structure and assess whether extra signals need explanation.
Setup
- Count distinct environments, then compare chemical shifts, proton integrations and resolved splitting with the proposed structure.
- Explain solvent and reference signals before assigning unexpected peaks as impurities.
Operating checks
- Exchangeable O–H and N–H signals can shift, broaden or disappear; their integrals may be unreliable.
- Simple splitting rules have limits, and routine 13C peak areas do not directly count carbons. Combine NMR with other evidence.
Scope and limitations
- Scope
- Ethyl acetate (ethyl ethanoate).
- Limitations
- Ethanoic acid and ethanol form in the same reversible acid-hydrolysis reaction.
Related reactions
- Iodoform reaction: Ethanol → Triiodomethane products
Ethanol is oxidised and cleaved by alkaline iodine to give triiodomethane and methanoate.
- Partial oxidation: Ethanol → Ethanal
Ethanol is oxidised to ethanal.
- Oxidation: Ethanol → Ethanoic acid
Ethanol is oxidised to ethanoic acid.
- Reduction: Ethanal → Ethanol
Ethanal is reduced to ethanol.
- Esterification: Ethanoic acid → Ethyl acetate
Ethanoic acid and ethanol combine reversibly to form ethyl acetate and water.
- Esterification: Ethanol → Ethyl acetate
Ethanoic acid and ethanol combine reversibly to form ethyl acetate and water.
- Acid hydrolysis: Ethyl acetate → Ethanoic acid
Ethyl acetate and water react reversibly to form ethanoic acid and ethanol.
- Hydration: Ethene → Ethanol
Ethene gives ethanol through hydration.
- Dehydration: Ethanol → Ethene
Ethanol gives ethene through dehydration.
- Intermolecular dehydration: Ethanol → Diethyl ether
Protonation turns one ethanol OH group into a better leaving group. The oxygen of another ethanol molecule displaces water, and deprotonation gives diethyl ether; stronger dehydration conditions instead favour ethene.
- Hydrolysis: Bromoethane → Ethanol
Hydroxide attacks the saturated carbon bearing bromine while the C-Br bond breaks. This primary-substrate SN2 route replaces bromide with OH and preserves both carbon atoms; aqueous conditions favour this branch over elimination.
- Acid hydrolysis: Ethyl butyrate → Ethanol
Water attack and proton transfers permit the ethoxy fragment to leave as ethanol. Re-forming the carbonyl produces butanoic acid on the other branch.
References
- Hydrolysing estersJim Clark · Chemguide · 2016
Named molecular examples and reaction scope, checked 2026-09-08.
- Chemistry Vignettes: Mechanisms of Esters and AmidesRoyal Society of Chemistry · RSC Education
Acid-catalysed ester hydrolysis.
- Teaching distillation’s apparatus and stagesRoyal Society of Chemistry · RSC Education
Fractionating columns improve separation of liquids with closer boiling points; ethanol/water distillate need not be pure ethanol.
- Nuclear magnetic resonance spectroscopy: introductionRoyal Society of Chemistry · RSC Education
Nuclear environments and structure identification with 1H and 13C NMR.
- Pearson Edexcel International Advanced Level Chemistry Student Practical GuidePearson Education Limited · Pearson qualifications · 2018
Supports the practical distinctions between reflux, distillation, liquid-liquid separation, washing and drying in organic preparations.
- Reflux and distillation – practical videosRoyal Society of Chemistry · RSC Education
Explains the different purposes and apparatus arrangements for reflux and distillation, including organic preparation and work-up.