The acid-catalyzed hydration of an alkene like 2-methylpropene to form 2-methylpropan-2-ol involves a three-step mechanism with two intermediates. The reaction proceeds as follows:1. Protonation of the alkene: In the first step, the alkene 2-methylpropene reacts with a strong acid, usually sulfuric acid H2SO4 or hydrochloric acid HCl , to form a carbocation intermediate. The double bond of the alkene attacks a proton H+ from the acid, resulting in the formation of a more stable carbocation. In this case, the carbocation formed is a tertiary carbocation, which is more stable due to hyperconjugation and inductive effects.Intermediate 1: CH3 2C+ CH3 22. Nucleophilic attack by water: In the second step, a water molecule acts as a nucleophile and attacks the carbocation formed in the first step. This results in the formation of an oxonium ion intermediate, where the oxygen atom of the water molecule is now bonded to the carbocation.Intermediate 2: CH3 2C OH2+ CH3 23. Deprotonation: In the final step, another water molecule or a base present in the reaction mixture abstracts a proton from the oxonium ion intermediate, resulting in the formation of the final product, 2-methylpropan-2-ol, and regenerating the acid catalyst.Product: CH3 2C OH CH3 Overall, the acid-catalyzed hydration of 2-methylpropene to form 2-methylpropan-2-ol involves a three-step mechanism with two intermediates: a carbocation and an oxonium ion.