Question

Distinguish between ethane, ethene and ethyne on the basis of their chemical test.

Answer 1

Compound	Chemical test	Observation
Ethane	Add bromine water to ethane.	Ethane does not decolourise bromine water because it is a saturated hydrocarbon.
Ethene	Add bromine water to ethene. Then add ammoniacal silver nitrate solution.	Ethene decolourises bromine water, but it does not give any precipitate with ammoniacal silver nitrate solution.
Ethyne	Add bromine water to ethyne. Then add ammoniacal silver nitrate solution.	Ethyne decolourises bromine water and gives a white precipitate of silver acetylide with ammoniacal silver nitrate solution.