alkanes and alkenes

alkanes general formula

Cn H2n+n

word beginning with s to describe alkanes

saturated

why are alkanes saturated

no c=c double bonds —> each carbon has made its maximum of 4 bonds

bonding in alkanes

covalent

alkane reaction with halogens

MUST BE IN UV RADIATION

substitution:

halogen + alkane —> halogenoalkane + hydrogen halide

example of ethane reaction with bromine

bromine + ethane —(UV)—> bromoethane + hydrogen bromide

alkene functional group

C=C

alkene general formula

Cn H2n

word beginning with u to describe alkenes

unsaturated - contains C=C double bonds

alkene reaction with bromine

addition:

alkene + bromine —> dibromoalkane

involves removal of carbon double bond

example of bromine reaction with ethene

ethene + bromine —> dibromoethane

difference between alkane and alkene reactions to bromine water

alkanes don’t react —> water remains orange

alkenes react —> water turns colourless