PAG 5.3: Oxidation of Ethanol
Oxidation of ethanol
- Primary alcohols can be oxidised to form aldehydes which can undergo further oxidation to form carboxylic acids
- When ethanol is oxidised, ethanal is produced and when oxidised further ethanoic acid will be formed
Synthesis and purification of ethanal and ethanoic acid
- Carefully add 20 cm3 of acidified potassium dichromate(VI) solution, K2Cr2O7 (aq), to a 50 cm3 pear-shaped flask and cool the flask in an iced water bath
- Set up the reflux apparatus keeping pear shaped flask cool
- Place anti-bumping granules into the pear shaped flask
- Measure out 1 cm3 of ethanol
- Using a pipette, slowly add the ethanol drop wise into the reflux condenser
- When the ethanol has been added remove the ice bath and allow to warm up to room temperature
- Position the flask over an electric heater or in a water bath and heat for 20 minutes
- Ethanol is flammable, therefore. naked flames should not be used when heating which is why the use of an electric heater or water bath is an important safety precaution
- Purify the product using distillation apparatus
Reflux apparatus for the oxidation of ethanol to ethanoic acid
Oxidation of ethanol by acidified K2Cr2O7 to form an aldehyde by distillation
