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 complete the reaction. In this experiment the alkene is norbornene and the product is exo-norborneol: The mechanism involves the formation of a carbocation by addition of a proton to the double bond of norbornene. In the following step, the less sterically hindered side of the carbocation is subjected to the nucleophilic attack of water leading to…show more content… Experimental Results
Weight of Crude Norborneol (mg) .153g—153mg
Percent Yield for Crude Product 25.93%
Melting Point of the Product —Range 99°C -112.2°C 13.2°C
Literature Source (ChemSpider) Melting Point 124 to 126 °C
Discussion:
The acid-catalyzed addition to a carbon-carbon π (pi) bond to result in an alcohol is referred to as hydration, which is the reverse reaction of a dehydration reaction. The two reactions were in equilibrium, the point of equilibria depends on the initial conditions. During this experiment sulfuric acid and H_2 O was added to norbornene to produce exo-norborneol. The purpose of the addition of water is to enhance the hydration reaction to reach completion. Sulfuric acid was favored over other acids because the anion produced is not a stronger nucleophile than water, so the nucleophilic attack will be carried out by water to result in alcohol. Throughout the experiment, sulfuric acid deprotonated to yield an anion and a proton. The steric hindrance from the surrounding groups attached to the carbocation caused the nucleophilic attachment of water occurs only in the exo-