Final answer:
The treatment of an alkene with H2 in the presence of a catalyst is known as hydrogenation, where hydrogen is added to the double bonds of an alkene to form an alkane.
Step-by-step explanation:
When an alkene is treated with H2 in the presence of a catalyst, the process is known as hydrogenation. This is a type of addition reaction where hydrogen atoms are added to the double bond of an alkene, effectively converting it into an alkane. A common example would be the hydrogenation of ethene (C2H4), which, in the presence of a catalyst such as platinum (Pt), would yield ethane (C2H6). Hydrogenation is an important process in the food industry, for example, in converting vegetable oils to solids such as margarine.
Polymerization, on the other hand, is a reaction where monomer units, like ethylene, react to form a polymer chain, such as polyethylene. This process is not the same as hydrogenation. Oxidation refers to the addition of oxygen or the removal of hydrogen from a molecule; while esterification is a reaction where a carboxylic acid and an alcohol combine to form an ester, none of which describes the treatment of an alkene with hydrogen in the presence of a catalyst.