Question

How is ethyne converted to

(i) ethene

Answer 1

Ethyne $\left({\mathrm{C}}_2{\mathrm{H}}_2\right)$ gives addition reaction with Hydrogen $\left({\mathrm{H}}_2\right)$ and Halogens because the triple bond is highly reactive in nature.

Reaction

Ethyne reacts with one mole of Hydrogen in the presence of Palladium $\left(\mathrm{Pd}\right)$ catalyst to gives Ethene $\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$

The chemical reaction is given below:

$$\begin{gathered} \mathrm{H}-\mathrm{C}\equiv \mathrm{C}-\mathrm{H}+{\mathrm{H}}_2\stackrel{\mathrm{Pd}}{\to }{\mathrm{CH}}_2={\mathrm{CH}}_2 \\ \mathrm{Ethyne}\mathrm{Hydrogen}\mathrm{Ethene} \end{gathered}$$