Alkenes

Describe structure of alkenes?

• unstaturated hydroarbon with C=C bond

• pi bond due to sideways overlap of adjacent 2 p-orbitals above + below bonding atoms

• pi bonds have high electron density

What are stereoisomers?

molecules with same structural formula but different arrangement

Describe E/Z + cis-trans isomerism

• E = diferent side

• Z = same side

• cis = same side with H

• trans = different side with H

How to use CIP to identify E/Z isomers?

higgher priority groups have higher atomic numbers

Hydrogenation of alkenes

forms alkanes
nickel catalyst + H2

Halogenation with halogens + how to test

forms dihaloalkanes

electrophilic addition

test using bromine water

Halogenation using hydrogen halides

forms haloalkanes

electrophilic addition

Hydration reactions

forms pri + secon alcohols

steam + acid catalyst H3PO4

What are the useful ways of dealing with waste polymers?

• Combustion - for energy production like electricity

• Feedstock for Cracking - to produce plastics + other chemicals

• Recycling - organise and recycle

Why are biodegradable polymers useful?

decompose into natural non-toxic substances so reduce pollution