The acid-catalyzed addition of water to a carbon-carbon double bond is the hydration of alkenes, this leads to the formation of an alcohol. An equilibrium is established between two competing processes; hydration is the opposite of a dehydration reaction. The position of the equilibrium is determined by the conditions of the reaction; hydration of a double bond demands an excess of water to move the reaction towards completion, and dehydration of an alcohol demands the removal of water in order to