alkenes Flashcards
why are alkenes more reactive then alkanes ?
unsaturated there is scope to add atoms onto the molecule ether end to make it saturated
the double bond has high electron density it makes alkenes susceptible to reactions with molecules that have partial postive charges
what is a structural isomer
same molecular formula different structural formula
why is a tertiary carbocation more stable than a primary carbocation
the postive inductive effect
the ability of an alkyl group to realise electron density through a covalent bond
how does a halide ion become partially positive on electrophilic addition reaction with halogens
as the halogen approaches the double bond the electron rich double bond repels electron density from one halogen atom onto the other an induced dipole
direct hydration conditions
high temp 300-600C
high pressure 70 atm
catalyst of concentrated H3PO4
what is addition polymer
long chain formed from many monomers and no other products formed
what are plasticers
the properties of some polymers can be altered through the use of plasticers
these are small molecules which fit in the gaps between polymer chains allowing them to slide past each other
e.g PVC is rigid enough to make drain pipes but with plasticers can be flexible to make aprons
how are properties of polymers determined by the way polymerisation is carried out
low density polyethylene
high temp + high pressure = lots of branches which can’t stack well resulting in a light flexible plastic
high density polyethylene
room pressure + room temp +ziegler nata catalyst = straight chain that pack tightly
describe the mechanical recycling process
plastics sorted into different types and washed
ground into pellets
the pellets are then melted down and remoulded
describe the feedstock recycling process
plastics are sorted into different types
heated to a temperature that breaks there polymer bonds
these are then repolymerised
to form new plastics
what are the issues with recycling plastics
only done a finite amount of times before structural integrity starts to fail so they need to be disposed
