Alkenes Flashcards
What is the general formula for an alkene?
CnH2n
Why are alkenes unsaturated molecules?
C=C
Why are alkenes so reactive?
Due to high electron density of C=C
What are electrophiles?
Electron pair acceptors
What is an intermediate?
A reactive species that forms in the middle of a reaction
How do you display sulfuric acid in the electrophilic addition reactions?
H - OSO3H (with partial charges)
What is the colour change when an ALKANE reacts with bromine water?
None
Describe the colour change when an alkene reacts with bromine water
Orange —> Colourless
What reacts with alkenes to produce halogenoalkanes?
Hydrogen halides
How do you know which product is major or minor?
Through stability of carbocation
What is the least stable carbocation?
Primary (only bonded to one other carbon)
What is the most stable carbocation?
Tertiary (bonded to 3 other carbons)
TRUE OR FALSE: Less stable carbocations are more likely to be produced
False
Which type of alkene can produce two products in electrophilic addition?
Unsymmetrical alkenes
What are polymers made of?
Long chains of monomers
State 2 examples of natural polymers
DNA, Cellulose, Starch
Give 2 examples of synthetic polymers
Nylon, Kevlar
What polymer is made of ethene monomers?
POLYethene
Why are addition polymers so inert?
Main chain is non-polar
Describe bonding within polymers
Covalent bonds are very strong
Do polymers have strong intermolecular forces between chains?
No, weak intermolecular forces
Why are longer, straight-chain polymers more rigid?
Stronger VDW’s
How plasticisers increase flexibility of polymers?
By pushing polymer chains apart by getting inbetween chains
How do plasticisers affect intermolecular forces of polymers?
- Reduced strength of intermolecular forces as they are further away
