The hydration of alkenes is a significant chemical reaction in which water is added to an alkene, resulting in the formation of an alcohol.

To elaborate, this reaction occurs when an alkene is treated with water in the presence of a strong acid catalyst, typically sulfuric acid ($\text{H}_2\text{SO}_4$) or phosphoric acid ($\text{H}_3\text{PO}_4$). This process is categorized as an addition reaction, where a water molecule adds across the double bond of the alkene. The product of this reaction is an alcohol, which is an organic compound characterized by the presence of a hydroxyl ($-\text{OH}$) functional group.

The mechanism of this reaction involves the formation of a carbocation intermediate. Initially, the acid donates a proton ($\text{H}^+$) to the alkene, resulting in the creation of a carbocation. This positively charged intermediate is then attacked by a water molecule, which donates an electron pair to form a covalent bond with the carbocation. Subsequently, another water molecule abstracts a proton from the newly formed compound, leading to the production of the alcohol.

This hydration reaction is pivotal in organic chemistry, as it facilitates the synthesis of alcohols from alkenes. It is crucial to recognize that the reaction is regioselective; the water molecule adds to the carbon atom of the double bond that is bonded to the greatest number of hydrogen atoms. This observation is encapsulated in Markovnikov’s rule.

In conclusion, the hydration of alkenes involves the addition of water to an alkene in the presence of an acid catalyst, yielding an alcohol. The reaction proceeds through the formation of a carbocation intermediate and adheres to Markovnikov’s rule.