Hydrogenation of Ethylene

In organic chemistry, addition reactions are key transformations that involve the addition of reactants to a double or triple bond, resulting in the formation of new single bonds. One common example of an addition reaction is the hydrogenation of alkenes, where hydrogen gas is added across the carbon-carbon double bond to form alkanes.

Consider the following reaction: Ethylene (C₂H₄) is reacted with hydrogen gas (H₂) in the presence of a catalyst, such as platinum (Pt). What is the primary product of this addition reaction?