
home	test	exam	game	contact

Hydration of Alkenes

Key Concepts

Hydration of alkenes is an addition reaction.
Water adds across the alkene's double bond.
This addition follows Markovnikov's rule.
(the H⁺ of H₂O goes to the C atom that has the greatest number of H atoms)
Used to produce industrial ethanol from ethene.
General Equation:

alkene + water H⁺
→ alkanol

H⁺ represents a dilute, strong acid such as dilute sulfuric acid.

Animated Tutorial

Examples

Hydration of ethene (ethylene):

ethene
(ethylene)

water

H⁺
→

ethanol
(ethyl alcohol)

C₂H₄

H₂O

H⁺
→

C₂H₅OH

H \|		H \|
C	=	C
\| H		\| H

H-O-H

H⁺
→

	H \|		H \|
H-	C	-	C	-OH
	\| H		\| H

Hydration of propene (propylene)

There are two possible products resulting from the addition of water to propene, 1-propanol and 2-propanol.

Markovnikov's Rule predicts that 2-propanol will be the major product, while the other structural isomer, 1-propanol, will be only a minor product of the reaction.

propene
(propylene) + water H⁺
→ 2-propanol
(major product) + 1-propanol
(minor product)

C₃H₆ + H₂O H⁺
→ H₃C - CHOH - CH₃
(major product) + CH₃ - CH₂ - CH₂OH
(minor product)

H
| H
|

C = C - C -H

|
H |
H |
H

+ H-O-H H⁺
→

H
| OH
| H
|

H- C - C - C -H

|
H |
H |
H

+

H
| H
| H
|

HO- C - C - C -H

|
H |
H |
H