Question 12.9: Propose a three-step reaction mechanism for the acid catalyz...

Step 1: Add a proton. Reaction of the carbon–carbon double bond with H^+ gives a 3° carbocation intermediate.

Step 2: Reaction of the carbocation intermediate with water completes the valence shell of carbon and gives an oxonium ion.

Step 3: Take a proton away. Loss of H^+ from the oxonium ion completes the reaction and generates a new H^+ catalyst.