Question

Take about 3 ml of ethanol in a test tube and warm it gently in a water bath. Add a 5% solution of alkaline potassium permanganate drop by drop to this solution. What happens to the colour of potassium permanganate added initially and then in excess? Give reason. Name the product of this reaction

Answer 1

Explanation:

The colour of KMNO4 will remains same

the product is CH3OOH

Answer 2

The purple colour of potassium permanganate added initially discharges but when it is added in in excess, then the purple colour remains the same.

- Actually, alkaline potassium permanganate (Baeyer's reagent) is an oxidising agent.

- It oxidises ethanol in to ethanoic acid according to the following reaction :

CH₃CH₂OH + 2[O] → CH₃COOH + H₂O

- Due to this, the colour discharges.

- But as soon as the oxidation is complete, then further addition of excess potassium permanganate imparts the purple colour to the solution.