Question

Which of the following compounds are gem-dihalides?

(i) Ethylidene chloride

(ii) Ethylene dichloride

(iii) Methylene chloride

(iv) Benzyl chloride

Answer 1

(i) Ethylidene chloride

(iii) Methylene chloride

Explanation:

Gem-dihalides are those dihalides in which two halogen atoms are bonded to the same carbon atom.

(i) \[\ce{\underset{Ethylidene chloride}{Cl2 - CH - CH3}}\]

(ii) \[\ce{\underset{Ethylene dichloride}{Cl - H2C - CH2 - Cl}}\]

(iii) \[\ce{\underset{Methylene chloride}{CH2Cl2}}\]

(iv)  

   Benzyl chloride

So, in (i) and (iii) two halogen atoms are present on the same carbon atom and they are termed gem-dihalides.