1. Ethene gas decolourises bromine solution and potassium permanganate solution. But, ethane gas does not change the colour of these solutions.
2. Ethyne gas forms a white precipitate with ammonical solution of silver nitrate and red ppt. with ammonical solution of copper (I) chloride. But, ethane does not respond to such tests.
|Bromine Test Add a few drops of sol. of bromine in carbon tetra-chloride to the hydrocarbon.||No change takes place.||The red colour of bromine is decolorised.||The red colour of bromine is decolorised.|
|Alkaline Potassium Permanganate Test: Add a few drops of alkaline pot. permanganate sol. To the hydrocarbon.||No change takes place.||The purple colour of Potassium permanganate is decolorised.|
The purple colour of potassium permanganate is decolorised.
|(iii)||Ammoniacal Cuprous Chloride Test: Add a few drops of ammoniacal cuprous chloride sol. to thehydrocarbon.||No change takes place.||No change takes place.|
A red ppt. of copper acetylide is formed.