Question

3ml of ethanol is taken in a test tube an warmed gently in a water bath . a 5% solution of alkaline potassium permanganate is added first drop by drop to this solution , then in excess.
i) how is 5% solution of KMnO4 prepared
ii) state the role of alkaline potassium permanganate in this reaction. what happens on adding it in excess
iii) write the chemical equation for this reaction​

Answer 1

1. Answer: Add 5ml of potassium permanganate to 100ml of water = 5%
2. Kmno4 oxides the ethanol to oxalic acid excess can make the colour pink disappear (Kmno4 colour)
3. 2KMnO4 + 3C2H5OH → 2MnO2 + 3CH3CHO + 2KOH + 2H2O

Thanks hope it helps

Answer 2

5 % solution of potassium permanganate can be prepared by adding 5ml of potassium permanganate to 100ml of water.

● The concentration of 5ml of potassium permanganate in 100ml of water denotes the percentage of potassium permanganate.

● The role of potassium permanganate Kmno4 in the mentioned reaction in the question is potassium permanganate oxides the ethanol to form oxalic acid.

● The excess addition results in disappearance of pink colour of potassium permanganate.

● The balanced chemical reaction of the above mentioned reaction is:

2KMnO4 + 3C2H5OH → 2MnO2 + 3CH3CHO + 2KOH + 2H2O