Alkenes

• Alkenes are unsaturated because they have a double carbon bond
• alkenes are more reactive than alkanes
• alkenes have a general formula of CnH2n
• In a large amount of oxygen alkenes undergo complete combustion
• there is not enough oxygen in the air so when burned they undergo incomplete combustion
• in complete combustion they have products of carbon dioxide and water
• in incomplete combustion they also produce water and carbon dioxide but have extra products of carbon and carbon monoxide (The silent killer)
• Carbon monoxide is colourless, odorless and tasteless.
• incomplete combustion results in a smoky yellow flame and less energy release
• a functional group is a group of atoms that act similarly when a reaction occurs
• all alkenes have a functional group C=C so they react similarly
• Alkenes react by addition reactions
• addition reaction are when the C=C bond opens and becomes saturated and a new atom is added to each molecule
• Hydrogen can react with alkenes to form saturated alkanes over the presence of a catalyst
• when alkenes react with steam a alcohol is formeed
• The alkene reacts with steam and water crosses the double bond
• alkenes also have addition reactions with halogens to make saturated molecules
• each carbon bonds with a halogen
• bromine would form dibromoethane