test 4 - copy
saturation
the measure of amt of bonds carbon has formed w/hydrogen
(higher is more bonds)
ene/yne is less saturated bc of double and triple bonds
what is cyclic
when carbon atoms are arranged in a ring
what does the compound being mor branched mean
lower boiling point as molecules are pushed further apart there is less dispersion force and thus less energy required to break the existing dispersion forces
alkanes use
burning as energy
alkenes use
very reactive so often used in chemistry
alkynes use
good source of energy when oxygen is thrown at it
are compounds with alcohol soluble as alcohol is but the carbon hydrogen bond is not
when smaller chain it is soluble as there is enough solubility to be soluble but when the chain gets larger is becomes less soluble
if the addition group is not on the end of the chain but not in the middle what is it
a secondary bond
less reactive than primary
if the bonded group is in the middle of the chain what is it
tertiary bond
least reactive
alcohol group
OH
carboxylic acid group
COOH
what does a bigger chain with a carbon chain mean
less soluble in polar bc the chain is nonpolar
higher b/mp bc of more dispersion forces so more energy required to break the bonds
what is an ester
a carboxylic acid and an alcohol (wirh H2SO4 as a catalyst)
how to name ester
alcohol and then acid suffix
eg methyl ethanoate
how can an estee be reversed back
hydrolosis
negatives of fossil fuels
finite
CO2/carbon neutreality
greenhouse gases
positives of fossil fuels
cheap/money
theres a lot
the infeastructure is already based around them
how to break down biomass
catalysts which are transitional metals and expensive
bacteria that may escape and ruin crops
ionic liquids which are expensive
fossil fuels and biomass diff chemically
fossil are straught chain hydrocarbons
biomass more complex structures (rings) (less carbon)
cellulose
long branched polymer of glucose
in all plants
hard to break down
lignin
plastic properties
glue that holds cellulose together
must be destroyed and bleached to get the cellulose
monomer
simple molecules
link together (polymerisation)
form polymer
can be multiple molecules linking together
what is a polymer
a string of monomers forming a chain
natural polymers
made of proteins and cellulose
plants and animals (cellulose/proteins)
plants in natural polymers
many contain starch
cellulose and starch contain sugar monomers
formed by condensation polymerisation
examples of natural plant polymers
wood
linen
cotton
silk
rubber
animals as natural polymers
made of proteins
made by condensation polymerisation
examples of natural polymers in animals
skin
muscle
organ
enzymes
synthetic polymers made of what
fossil fuels or biomass
what synthetic polymers o
commonly called
plastics (most)
js means smt pliable or moukdavke in final or late stages
what are addition polymers
alkenes
eg polythene or rubber
what is addition polymerisation
when bonds break and electrons are freed and bond with next monomer
this makes smaller chains ideal and alkenes necessary
what is condensation polymerisation
when the function group of one chain contacts another, giving the chain two functional groups (difunction)
what does condensation polymerisation release
a small molecule (usually water)
what is a free radical
when UV is theown at compounds and they split
H2 plus UV
H plus H (high energy)
properties of polymers
dispersion forces (no polarity bc long carbon chain)
longer chain= stronger dispersion
lightweight, insulators, flammable
properties of thermoplastics
soften when heated
(heating overcomes bonds)
layers slide over one another
intermolecular forces in thermoplastics
hydrogen bonds, dipole dipole, dispersion (mostly dispersion bc forces weak)
properties of thermoset
decompose/burn when heated (damages covalent bonds)
cannot be remoulded
rigid, hard and resistent to heat
intramolecular bonds in thermoset
covalent bonds (called cross links)
elastomers properties
inbeteeen set and plastics
chain slides to a point and then springs back (bc covalent)
hard to recycle but not as hard as set
intramolecular in elastomers
covalent bonds (few cross links)
choice of polymers factors
monomer (polarity etc)
length of chain (longer is stronger dispersion)
branching (how much)
polar monomers properties
dipole dipole bonds
eg PVC which is harder/rigider than teflon
what are copolymers
when two or more polymers are used in smt
what does branching effect
more means weaker dispersion
more means softer/more flexible
what is crystallinity
when polymers are arranged in a lattice (stronger intermolecular forces)
what are amorphoe regions
when the polymers are randomly tangled together (weaker inter forces)
what are additives
when plasticisers (small molecules) are stuffed in between chains
this separates the chains (changes properties)
advantages of polymers
big variety
not reactive
chem/corrosion resistent
some recycleable
low density
mallieable
strong
modifiable properties
disadvantages of polymers
many non renewable
microorganisms cant break down most
thermoplastics not very durable
break/scratch/crack easy
produces toxic gasses
difficult to recycle
general ruling for recycling (i made this up)
really hard or really soft plastics are not recycleable and inbetween like soft drink or mik bottle are
does biomass mean biodegradable
no
degradable meanin
can break down into very small but not entirely
biodegradable meaning
can completely break down
compostable meaning
can degrade fully in warm, moist enviro (supports plant life)
recycleable meaning
can be reprocessed
polylactic acid properties
useful
soluble in organis solvents
made from condensation reactions
what is an ester link
oxygen betwen two carbons
what is biopolyethene
thermoplastic polymer
same properties as polyethen but made from cellulose
how many carbons is a monomer typically
two or more (it is purely one length of the pattern)