How will you convert ethene to ethane?

Hint: Ethene and ethane belong to the alkene and alkane groups respectively. Alkene reacts rapidly with hydrogen to form alkanes in the presence of a catalyst.

Complete step by step answer:
Alkene is an unsaturated hydrocarbon that contains a double bond.
The conversion of alkenes to alkanes involves a process known as catalytic hydrogenation. In this process, hydrogen is added to the alkene in the presence of a fine catalyst like nickel, platinum or palladium. These catalysts help in breaking the double bond of the alkene into a single bond to form alkane.This reaction is known as Catalytic hydrogenation because it involves a catalyst that is used to drive the reaction and helps to produce alkanes as a product.

In the given case, ethene (${C}_{2}{H}_{4}$) is an alkene and thus can be converted to ethane (${C}_{2}{H}_{6}$), an alkane, through the process of catalytic hydrogenation or addition of hydrogen which is also known as reduction process.
The reaction involved in this process is as follows:

${ CH }_{ 2 }={ CH }_{ 2 }+{ H }_{ 2 }\xrightarrow [ Nickel ]{ } { CH }_{ 3 }-{ CH }_{ 3 }$

In the above reaction, the double bond in ethene is replaced by hydrogen and ethane is obtained as the product.

Note: The conversion of unsaturated alkene to saturated alkane should be done in the presence of a catalyst so that it can go at a reasonable rate or else it would require very high temperatures for the reaction to proceed.