Objective
- To study oxidation of alcohols using oxidizing agent
Materials required:
- Ethanol
- KMnO4
- NaHCO3
- dil. H2SO4
- spirit lamp
- test tubes
- delivery tube
Procedure
- Add 0.5g of KMnO4 in a test tube and add 10mL water. Add 2-3 drops of dil H2SO4 to it
- Take 3 mL of ethanol in a test tube and add two or three drops of KMnO4 solution and stir till it decoloizes. Keep on adding KMnO4 solution drop-wise & stirring till it decolorizes
- Warm the mixture gently over spirit lamp and shake the reaction mixture occasionally.
- Warm the solution slowly over spirit lamp till the reaction mixture decolourises (DO NOT BOIL – ethanol vapors are highly flammable )
- Add a pinch of sodium hydrogen-carbonate (NaHCO3) to the solution. Check for effervescence
Observations and Findings:
- Effervescence on addition of NaHCO3
Conclusions:
- Effervescence on addition of NaHCO3 confirms the presence of ethanoic acid
Theory:
- An oxidation process involves gain of oxygen by the elements or compounds. Alcohol on oxidation with an oxidising agent (such as alkaline potassium permanganate solution) get oxidised to a carboxylic acid. The completion of reaction is characterized by the decolourisation of potassium permanganate solution
