Question

Write the reaction of ethene with hydrogen.

Answer 1

In an organic reaction, the reagent reacts with a reactant molecule to produce an intermediate which is converted into final products.

Alkenes contain double bonds between the Carbon $\left(\mathrm{C}\right)$ atoms so it is an unsaturated hydrocarbon.

In the reaction of an alkene with a Hydrogen $\left(\mathrm{H}\right)$ molecule in the presence of a metal catalyst, the Hydrogen molecule is added to the double bond to form the saturated product.

So this addition reaction is known as a hydrogenation reaction.

The reaction of Ethene $\left({\mathrm{C}}_2{\mathrm{H}}_4\right)$ with Hydrogen can be written as:

$$\begin{gathered} {\mathrm{CH}}_2={\mathrm{CH}}_2+\mathrm{H}-\mathrm{H}\stackrel{\mathrm{Ni}}{\to }{\mathrm{CH}}_3-{\mathrm{CH}}_3 \\ \left(\mathrm{Ethene}\right)\left(\mathrm{Hydrogen}\right)\left(\mathrm{Ethane}\right) \end{gathered}$$