Question

State the condition required for the preparation of ethyne from ethylene dibromide.

Answer 1

• Ethylene can be prepared from ethylene dibromide by boiling the solution.
• Ethyne is prepared from ethylene dibromide by reacting with hot concentrated alcoholic KOH.
• $$\begin{gathered} \mathrm{CHBr}={\mathrm{CH}}_2\left(\mathrm{aq}\right)+{\mathrm{NaNH}}_2\left(\mathrm{aq}\right)\to \mathrm{CH}\equiv \mathrm{CH}\left(\mathrm{aq}\right)+\mathrm{NaBr}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right) \\ \mathrm{Ethylene}\mathrm{bromide}\mathrm{Sodium}\mathrm{amide}\mathrm{Ethyne}\mathrm{Sodium}\mathrm{bromide}\mathrm{Hydrogen} \end{gathered}$$