alkenes

• alkenes are a series of covalently bonded molecules containing hydrocarbons
• alkenes are commonly used as feedstocks for making plastics such as polyethene and polypropene
• alkenes are non polar covalent molecules meaning that they are insoluble in water
• alkenes can be collected by displacement of water
• the general formula for alkenes is CnH2n
• alkenes are much more reactive because they are unsaturated as they contain double bonds
• the c=c group is know as a functional group, this is what gives the molecule its chemical properties
• alkenes can go through an addition reaction to make an alkene, this is known as hydrogenation
• in addition reactions 2 different molecules join to make one single molecule
• reactions of alkenes:

  A) X is a halogen atom

  B) dihalogenoalkane

  C) halogenoalkane

  D) alcohol

  E) alkane

  
• hydration is when water is added to an alkene turning it into alcohol
• dehydration is when water is lost from an alcohol turning it back into an alkene
• isomers have the same molecular formula but a different structural formula
• the test for unsaturation is an example of an addition reaction
• unsaturated compounds quickly decolorise bromine