The acid-catalyzed hydration of alkenes is an electrophilic addition reaction that involves the addition of water H2O across a double bond C=C in the presence of an acid catalyst, typically a strong acid like sulfuric acid H2SO4 or phosphoric acid H3PO4 . The overall reaction results in the formation of an alcohol R-OH from the alkene. The mechanism proceeds through three main steps and involves the formation of intermediates.1. Protonation of the alkene:The first step involves the protonation of the alkene double bond by the acid catalyst. The alkene acts as a nucleophile and attacks a proton H+ from the acid, generating a carbocation intermediate. This step is the rate-determining step of the reaction.Intermediate: CarbocationThe carbocation is a high-energy intermediate, with a positively charged carbon atom. The positive charge is located on the carbon atom that was part of the double bond. The stability of the carbocation intermediate depends on the alkene's substitution pattern. More substituted carbocations tertiary > secondary > primary are more stable due to hyperconjugation and inductive effects.2. Nucleophilic attack by water:In the second step, the carbocation intermediate reacts with a water molecule. The oxygen atom in water, which is nucleophilic, attacks the positively charged carbon atom in the carbocation, forming a bond between the oxygen and carbon.Intermediate: Protonated alcoholThe result of this step is a protonated alcohol intermediate, with a positively charged oxygen atom.3. Deprotonation:In the final step, the protonated alcohol intermediate loses a proton H+ to another water molecule or the conjugate base of the acid catalyst, acting as a base. This step restores the neutral charge on the oxygen atom and forms the final alcohol product.Product: AlcoholThe overall result of the acid-catalyzed hydration of alkenes is the conversion of the alkene into an alcohol, with the addition of water across the double bond. The reaction follows Markovnikov's rule, meaning that the hydroxyl group OH will be added to the more substituted carbon atom, while the hydrogen atom H will be added to the less substituted carbon atom.