Alkenes and Alcohols (1st page) AQA CHEM2

Alkenes

• homologous series... same functional group, differ by CH2
  
• CnH2n
• Unsaturated
• Obtained in the petrolleum industry

Long chain hydrocarbon = short chain hydrocarbon + alkene

• Bromine goes colourless if an alkene is present
• C=C is a region of high electron density
• Ethene is a planar molecule as C=C restricts shape
  

Addition reactions

...small molecule joins onto an unsaturated molecule so together they form a saturated molecule

with Bromine

• test for unsaturation
• will go colourless

with HBr

Rule for where Br goes

secondary carbocation more stable than primary because

the methyl group donates electons as it is an electron donating group.

More stable one is the one with the most methyl groups atttached to the +

Mortovintor (not explanation)

one with most H atoms gets the Hydrogen

with Cold concentrated sulphuric acid

• Step one is done with cold sulfuric acid
• step 2 is when the carbocation is warmed and hydrolysed

Polymers
Polymer... a long chain of hydrocarbons (large molecule)

Monomer... small molecule. Join together in polymerisation. Repeating unit

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