Question

State the condition required for the catalytic hydrogenation of ethyne.

Answer 1

Ethyne gas is mixed with hydrogen gas and passed over heated nickel at 300°C when an addition reaction takes place with the formation of ethane gas.

$$\begin{gathered} {\mathrm{C}}_2{\mathrm{H}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)\underset{{300}^0\mathrm{C}}{\overset{\mathrm{Ni}}{\to }}{\mathrm{C}}_2{\mathrm{H}}_4\left(\mathrm{aq}\right) \\ \mathrm{Ethyne}\mathrm{Hydrogen}\mathrm{Ethene} \\ {\mathrm{C}}_2{\mathrm{H}}_4\left(\mathrm{aq}\right)+{\mathrm{H}}_2\underset{{300}^0\mathrm{C}}{\overset{\mathrm{Ni}}{\to }}{\mathrm{C}}_2{\mathrm{H}}_6\left(\mathrm{aq}\right) \\ \mathrm{Ethene}\mathrm{Hydrogen}\mathrm{Ethane} \end{gathered}$$