Alkenes

• Alkenes are hydrocarbons with a double bond between the carbon atoms
• The presence of the double bond means that it is unsaturated, this mean that the number of hydrogen atoms is fewer in alkenes
• ethene: C2H4
• propene: C3H6
• butene: C4H8
• pentene: C5H10
• Alkenes can react with hydrogen gas; called hydrogenation
• Alkenes can react with water to form alcohol; called hydration
• Alkenes can react with group 7 elements; called halogenation