Question

The product $(X)$ obtained in the following reaction is
$CH _{3} CHBr - CH _{2} Br + Zn \longrightarrow 'X'$

• A. $CH _{3} CH _{2}- \underset{\overset{|}{Br}}{C}H _{2}$
• B. $CH _{3} \underset{\overset{|}{Br}}{C}H - CH _{3}$
• C. $CH _{3} CH == CH _{2}$
• D. None of these

Answer 1

Answer: (C)

Dihalides in which two halogen atoms are attached to two adjacent carbon atoms are known as vicinal dihalides. On reaction with $Zn$, these form alkene by losing a molecule of $Zn X_{2}$ as shown below :
$\underset{\text{1,2-dibromo propane}}{CH _{3} CHBr} - CH _{2} Br + Zn \longrightarrow \underset{\text{propene}}{CH _{3} CH} == CH _{2}+ ZnBr _{2}$