3ml of ethanol is taken in a test tube and 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. Write a chemical equation for this reaction. (2024)

FAQs

What happens when 5% alkaline potassium permanganate is added to ethanol? ›

(a) On adding 5% alkaline potassium permanganate solution drop by drop to some warm ethanol, we would observe that the purple color of potassium permanganate starts disappearing. The product formed by this process is ethanoic acid that can turn blue litmus red.

In this case 5% alkaline solution is added drop by drop to warm ethanol, and due to its strong oxidizing property it oxidizes ethanol to ethanoic acid and it colour changes to brown due to the formation of .

a When ethanol is oxidised with alkaline potassium permanganate or acidified potassium dichromate it gets oxidised to form ethanoic acid.

(i) 5% solution of KMn04 is prepared by dissolving 5 grams of KMnO₄ in 100 ml of water. (ii) Alkaline potassium permanganate is adding oxygen to alcohol and converts it to acid. Hence, it acts as an oxidizing agent.

CH 3 CH 2 OH ( l ) + 2 [ O ] ( g ) → KMnO 4 ( alk ) , heat CH 3 COOH ( l ) + H 2 O ( l ) Ethanol Oxidation Ethanoic acid ( Acetic acid )

This is because the coloured permanganate ions of alkaline potassium permanganate are consumed to oxidise ethanol solution. When excess of alkaline potassium permanganate is added, the purple colour of alkaline potassium permanganate does not change. This is because there is no more ethanol left for the reaction.

When 5% alkaline potassium permanganate solution is added drop by drop to warm propyl alcohol (propanol) taken in the test tube, then its purple colour gradually disappears as it oxidizes the propanol to its respective carboxylic acid i.e propionic acid.

the tube is immersed in water bath as it contains alcohol and alcohol is easily flammable. by heating the alcohol directly ,it will catch fire. it is immersed in water bath so that alcohol doesn't catch fire.

Answer and Explanation:

(a) When Ethanol reacts with Sodium metal, it forms sodium ethoxide and hydrogen gas. (b) When Ethanol reacts with Potassium permanganate solution in basic condition, it forms ethanoic acid as potassium permanganate is a strong oxidising agent.

When ethanol is heated with alkaline potassium permanganate solution, it gets converted into ethanoic acid.

What happens when ethanol is warmed with acidified k2cr2o7? ›

In the further oxidation, ethanal is converted to ethanoic acid. You can also call ethanoic acid as acetic acid. It is a carboxylic acid. Hence, ethanol on reaction of acidified potassium dichromate form ethanoic acid.

The above reaction involves the formation of an ester (ethyl ethanoate) by heating ethanol and ethanoic acid in the presence of concentrated sulphuric acid. This reaction is called esterification reaction.

When potassium permanganate is heated it produces potassium manganate, manganese dioxide and oxygen gas.

When we place Potassium Permanganate crystals into the water, it's purple colour spreads throughout the water. This shows the diffusion property of particles of water and Potassium Permanganate, as due to this property only the dissolution and spreading of the colour of Potassium Permanganate takes place.

Organic chemistry

Dilute solutions of KMnO₄ convert alkenes into diols. This behaviour is also used as a qualitative test for the presence of double or triple bonds in a molecule, since the reaction decolorizes the initially purple permanganate solution and generates a brown precipitate (MnO₂).

Ethanol is oxidised by alkaline KMnO4 to oxalic acid. Ethanol is oxidised by alkaline KMnO4 to ethanoic acid. Assertion :The volume of 0.1M KMnO4 required to oxidise 20 ml of 0.1 M oxalic acid in acidic medium is 20 ml. Reason: 2 moles of KMnO4 = 5 moles of oxalic acid in acidic medium reaction.

When K M n O 4 added in excess, primary alcohol (ethanol) oxidised to carboxylic acid. On further addition, there will be no colour change as there is no alcohol to oxidised.

Hence, alkaline plays the role of an oxidizing agent in the reaction involving the conversion of an alcohol to corresponding carboxylic acid.

Physical Properties Of Potassium Permanganate – KMnO

It is soluble in water, acetone, acetic acid, methanol, and pyridine. It gets dissolved in ethanol and organic solvents. Potassium permanganate occurs in the form of monoclinic prisms, almost opaque with a blue metallic lustre.