Question

The reagent used for converting tetrabromoethane into ethyne is:

• A. Alcoholic KOH
• B. Conc. $H_{2}S{O}_4\text{at}{170}^{o}C$
• C. Aqueous potash
• D. Zinc dust

Answer 1

The correct option is D Zinc dust

Alc. KOH is used in preparation of acetylene from dihalides and Zn dust is used in preparation of acetylene from tetra halides.
Reaction:
$B{r}_{2}C{H}_2-C{H}_{2}B{r}_2+2Zn\stackrel{△}{\to }\underset{\text{Acetylene}}{H-C\equiv C}-H+2ZnBr$
1,1,2,2-tetrabromoethane