Question

Name two reagents which can be used to distinguish between ethene and ethyne.

Answer 1

Ethene and ethyne both of them are saturated hydrocarbons. They can decolourise potassium tetraoxomaganate and also Bromine water. Ethyne reacts with insoluble salts and gives certain reactions. The reagents which distinguish the ethane and ethyne are  ,

a)Ammoniacal silver nitrate $AgNO_3$  which is a Tollen’s reagent:

             Ethyne reacts with “Ammonical silver nitrate” and gives the desilver acetylide (white precipitate), ethene does not reacts with the Tollens reagent.

b)  Solution of “Ammoniacal cuprous chloride” is also one of the reagents to distinguish between the ethane and ethyne.

Answer 2

Explanation:

Ammonical silver nitrate solution(Tollen's reagent) is used to distinguish between ethene and ethyne.

Ethyne + tollens reagent --------> silver acetylide (white ppt)

Ethene+ tollens reagent---------->No reaction