mod 7 Flashcards
examples of:
- molecular formula
- condensed structural formula
- full structural formula
e.g C2H4, C6H14
____
____
what are organic compounds
molecules which contain carbon atoms and are found in all living organisms
what are hydrocarbons
hydrocarbons are organic molecules that consist of solely Carbon and Hydrogen atoms
SUFFIXES -
alkane
alkene
alkyne
single bond –> ane
double bond –> ene
triple bond –> yne
PREFIXES (no. of carbons in longest chain) -
1
2
3
4
5
6
7
8
9
10
meth
eth
prop
but
pent
hex
hept
oct
non
dec
position of double or triple bonds
- position is denoted by a number in between the prefix and the suffix
- count the carbons so the double or triple bond has the lowest locant
- has highest priority
side branch chains
- ethyl (CH3CH2)
- methyl (CH3)
position of side branch chains
- position number followed by the side chain name before the prefix (e.g 2,3-dimethylbutane)
- put prefixes (di, tri, tetra, etc.) before side chain names if more than one
- count side chains to have the lowest locant
key point in naming hydrocarbons
- determine longest carbon chain and type of hydrocarbon (i.e ane, ene or yne)
- choose a side to count from by assigning lowest locants
- if >1 side chain order them in alphabetical order and add prefix’s
what is a functional group
a distinctive chemical structure that is responsible for the chemical properties of a compound (types of bonds are their own functional group)
general formula for
- alkanes
- alkenes
- alkynes
- C(n)H(2n+2)
- C(n)H(2n)
- C(n)H(2n-2)
types of structural isomers
- chain isomers (formed by rearranging the carbon backbone into different chains)
- position isomers (formed by changing the position of functional groups to the carbon backbone)
- functional group isomers (formed with different functional groups)
what is a homologonous series
group of molecules in organic chemistry with similar structures and properties (e.g alkanes, alkenes, alkynes)
intramolecular bonding of alkanes
- single bonds are more stable than triple or double
- alkanes are unreactive in comparison
- single bonds weaker than double or triple (requires less energy to break)
intermolecular bonding of alkanes
- whole molecule is non-polar (only dispersion forces)
- as carbon chain increases, strength of dispersion forces increase
- branched chain isomers are weaker (decrease in SA)
addition reaction meaning
where a small molecule reacts with an unsaturated compound by breaking 1 or 2 pi bonds and adding across the former position of the pi bond
- symmetrical compound = 1 answer
- asymmetrical compound = 2 answer
hydrogenation of alkene meaning
addition reaction where hydrogen gas is added across the double bond to form an alkane.
- catalyst of Pd/C (palladium or granulated carbon)
ALKENE + H2 –> ALKANE
hydrogenation of alkyne meaning
addition reaction where hydrogen gas is added across the triple bond to form an alkene or alkane
- to produce alkane: catalyst of Pd/C
- to produce alkene: Lindlar catalyst or Pd poisoned with Pb
ALKYNE + H2 –> ALKANE
ALKYNE + H2 –> ALKENE
halogenation of alkene or alkyne meaning
an addition reaction where a halogen gas (e.g Cl2, Br2) is added across a pi bond to produce a halogenated organic compound
- no catalyst
- based on halogen it’s called bromination/chorination, etc.
ALKENE + HALOGEN2 –> ALKANE
ALKYNE + HALOGEN2 –> ALKENE
ALKYNE + 2HALOGEN2 –> ALKANE
hydrohalogenation of alkene or alkyne meaning
an addition reaction where a hydrogen halide (e.g HCl, HBr) is added across a pi bond to produce a halogenated organic compound
- no catalyst
- based on halogen it’s called hydrochlorination, etc.
naming halogenation compounds
- treat halogen as a side chain with the same prefixes, in alphabetical order and lowest locant
- F = Fluoro
- Cl = chloro
- Br = bromo
- I = iodo
what is hydration of alkene
is an addition reaction where water is added across the double bond to form an alcohol
- catalyst: diluted H2SO4 and 160C
- H2O spits into H and OH then adds
ALKENE + H2O –> ALCOHOL
what is an alcohol and how to name them
organic compounds with a hydroxyl group (OH= hydrogen bonding and dipole-dipole bonding)
- add suffix ‘al’ ot the end
- lowest locas of OH group
what is hydration of alkyne
is an addition reaction where water is added across the triple bond to form a ketone (rarely aldehyde)
ALKYNE + H2O –> KETONE/ALDEHYDE
- catalyst: H2SO4/HgSO3 and 160C
- there is an intermediate alkene/ol
what is an aldehyde and how to name it
has a carbonyl (C=O) group on a terminal carbon on the carbon chain
- add suffix ‘al’ at the end
- no locant needed
what is an ketone and how to name it
has a carbonyl (C=O) group anywhere but the terminal carbons on the carbon chain
- add suffix ‘one’ at the end
- lowest locant of C=O group
substitution reaction with alkanes
replacement of a hydrogen bonded to a carbon with an alternative side group, often a halogen
ALKANE + HALOGEN2 –> HALOALKENE + HYDROGEN HALIDE
- catalyst: UV light
- halogen spilts (one goes into carbon atom and the the other forms a hydrogen halide)
markovnikov’s rule for addition reactions
the hydrogen atom will bond to the carbon atom with a greater number of hydrogen atoms already attached to it
- in asymmetrical reagents this forms a minor and major product
classifying alcohols
- primary (1 carbon chain attached)
- secondary (2 carbon chains attached)
- tertiary (3 carbon chains attached)
combustion of alcohols
combustion of alcohols in oxygen produces CO2 and H2O in a highly exothermic reaction
ALCOHOL + O2 –> CO2 + H2O
- incomplete (CO or C) and complete combustion
- coeff of fuel/alcohol must be 1
dehydration of alcohols
dehydration of alcohols produces the corresponding alkene and H2O
ALCOHOL –> ALKENE + H2O
- catalyst: conc. H2SO4/H2PO4 and heat
- the H and OH must be removed from adjacent carbons and a pi bond added
alcohol substitution with hydrogen halides
alcohols are substituted with hydrogen halides to produce corresponding halogenated haloalkane and water
ALCOHOL + HX –> HALOALKANE + H2O
- catalyst: aqueous ZnX (Zn halogen)
- OH is substituted with halogen from hydrogen halide
order of alcohol reactivity
- tertiary
- secondary
- primary
order of acid reactivity
- HI
- HBr
- HCl
- HF
oxidation of alcohols
PRIMARY ALCOHOL –> ALDEHYDE –> CARBOXYLIC ACID
SECONDARY ALCOHOL –> KETONE
- catalyst: K2Cr2O7, dilute H2SO4 (strong oxidising agent) and heat
- take away OH’s H and add double bond to O
what is a carboxylic acid and how to name it
characterised by carboxyl group (COOH)
- drop the ‘e’ and add ‘oic acid’
substitution of halogenated organic compounds (haloalkane)
halogenated organic compound may undergo substitution with a metal hydroxide to produce an alcohol and salt
HALOALKANE + DILUTE NaOH –> ALCOHOL + SALT
- catalyst: acetone solvent and heat
substitution of halogenated organic compounds (tertiary haloalkane)
halogenated organic compound may undergo substitution with water to produce an tertiary alcohol and hydrogen halide
TERTIARY HALOALKANE + H2O –> TERTIARY ALCOHOL + HX
BP trends in alcohol
- as carbon chain increases so intermolecular forces increase so BP increases
- as carbon chain increases BP difference btw alkanes and alcohols decreases (dispersion forces dominate in alcohols)
- alcohols BP»»alkanes BP (always)
order of alcohols BPs
- primary
- secondary
- tertiary
dissolving alcohols in water process
2 sections:
1. alkyl (non polar and only interacts using dispersion forces)
2. hydroxyl (polar and only interacts using H-bonding and dipole-diple)
solubility of alcohols in water
alcohol solubility is proportional to (solute-solvent) - (solute-solute) - (solvent-solvent)
- memorise table
solubility trends of alcohol
- carbon chain increases = stronger dispersion forces = decrease solubility
- order of solubility (accessibility of OH group) = tertiary>secondary>primary
natural sources of hydrocarbons
fossil fuels (non-renewable resources) are produced by natural processes on the fossilised remains of dead organisms over millions of years
- DRILLING: drags water to the surface to extract it’s dissolved minerals
- FRACKING: water and other substances are blasted into a natural gas reserve to fracture rocks and extract minerals
enviro, eco and socio advantages of hydrocarbons extraction
ENVIRO = petroleum extraction reduces pressure on underground oil resevioures
ECO = relatively cheap fossil fuels are readily found and are a huge part of Australia’s economy
SOCIO = increases job opportunities
enviro, eco and socio disadvantages of hydrocarbons extraction
ENVIRO = drilling and fracking damages land; exposes heavy metals and radioactive substances
ECO = relatively high cost to establish
SOCIO = destroys tourist and Indigenous land
enviro, eco and socio advantages of hydrocarbons usage
ENVIRO = natural gas burns cleaner than wood; saves habitats
ECO = increase employment and SOL
SOCIO = increased int. travel and electricity usage
enviro, eco and socio disadvantages of hydrocarbons usage
ENVIRO = climate change caused by CO2 production; greenhouse affect; acid rain from NO2 and SO2 gases
ECO = global wealth inequality
SOCIO = degrades tourist attractions, human rights violation
what are biofuels
an alternate source of fuel that are renewable from plant material (e.g veggie waste, etc.)
- aim to be carbon neutral (no net release of carbon)
how are biofuels produced
from fermentation of glucose from natural sources (e.g sugar cane) for fuel
what is fermentation
is the process by which carbohydrates turn from alcohol to yeast and other microorganisms
advantages of biofuel
- carbon neutral as CO2 produced = CO2 absorbed by sugar cane plants
- burns cleanly due to ethanols partially oxidised nature
disadvantages of biofuel
- require expensive vehicle engine modifications to use
- transportation emits CO2
- lot of fuel needed (ethanol has low enthalpy of combustion)
- pungent fermentation waste
what is biogas
a mixture of methane and CO2 which is formed by harnessing the decomposition of organic materials by anaerobic bacteria
what is biodiesal
biodiesal is a mixture of esters which are produced by reacting vegetable oils or animal fats with base
what are amines and how to name them
amines are organic compounds containing a basic nitrogen atom with a lone pair
- primary amine: locant-alkylprefixan-locant-amine
- secondary amine: N-alkylprefixan-locant-amine
- tertiary amine: N-alkyl, N-alkylprefixan-locant-amine OR N,N-dialkylprefixan-locant-amine
amines properties
- has a polar NH2 group
- as carbon chain increases the basicity increases and solubility decreases
- in order of basicity tertiary>secondary>primary
- has hydrogen, dipole dipole and dispersion forces
- in order of BP tertiary<secondary<primary
amine production
an alcohol can undergo substitution with NH3 to produce a primary amine
SECONDARY ALCOHOL + AMMONIA –> PRIMARY AMINE + WATER
- NH3 splits into NH2 and H
carboxylic acid properties
- have polar carbonyl group (COOH)
- as carbon chain increases the acidity and solubility decreases
- in order of acidity tertiary<secondary<primary
- have hydrogen, dipole dipole and dispersion forces
what is an amide and how is it names
amides contain a carbonyl attached to a nitrogen atom and they are neutral
- drop ‘e’ and add ‘amide’
- main carbon chain MUST HAVE carbonyl group in it (CONH2)
amide production
amides are produced by the condensation reaction of carboxylic acid and an amine
CARBOXYLIC ACID + AMMONIA –> PRIMARY AMIDE + WATER
CARBOXYLIC ACID + PRIMARY AMINE –> SECONDARY AMIDE + WATER
CARBOXYLIC ACID + SECONDARY AMINE –> TERTIARY AMIDE + WATER
- catalyst: DCC and reflux conditions and 190C and 4hrs
amide properties
- have both NH and C=O groups
- have hydrogen, dipole dipole and dispersion
- as MM increases solubility decreases
- in order of BP primary>secondary>tertiary
aldehyde and ketone properties
- both have polar carbonyl groups (C=O)
- dipole-dipole and dispersion forces
- increase chain length = decrease in solubility
safety hazards
- always consult MSDS (material safety data sheet)
- organic substances are volatile, flammable, corrosive/caustic
- should wear PPE, have emergency shower and fume cupboard
- same disposal into waste bins
- if spill use solid NaHCO3 (amphiprotic)
what are esters and how to name them
esters are highly fragrant organic compounds that have a COO functional group bridging 2 alkyl groups
- 2 separate words
- replace ‘ol’ suffix of the alcohol with ‘yl’ as the first word
- replace ‘oic acid’ suffix of the carboxylic acid with ‘oate’ for the second word
ester production
esters are produced by the equilibrium/condensation reaction of an alcohol with a carboxylic acid called esterification
ALCOHOL + CARBOXYLIC ACID –><– ESTER + WATER
- catalyst: conc. H2SO4 and heat (increases ROR and yield, is a dehydrating agent and shifts equilibruim right)
- alcohols are volatile and heat would loose reactants so reflux is used
reflux in ester production
a procedure in which the reaction flask is continually heated while vapours emerging from it are guided through a condenser tube which cools the gases and condenses them back into the flask
- prevents loss of reagent
- allows reaction to perform at higher temps (increasing ROR)
important apparatus for esterification
- hotplate
- boiling chips (control the boiling by providing nucleation sites for bubbles to dissipate promote even boiling and prevent bumping
- condenser tube
purification of ester
- neutralise the excess acid by adding base Na2CO3
- add water to dissolve water soluble substances (e.g salts, etc.)
- add mixture to separating funnel to separate into a dense organic layer and more dense aqueous layer
- the aqueous at the bottom is removed
- repeat 3&4 multiple times
- use distillation to separate ester from other compounds
what are surfactants
soaps and detergents are surfactants and they are more effective at cleaning than water alone
- used to clean non-polar substances from surfaces
- soaps are produced from natural sources while detergent is made from artificial products
- surfactants have 2 parts: hydrophilic head and hydrophobic tail
parts of a surfactant
- polar hydrophilic head (water loving, interacts with water, H-bond and dipole dipole and dispersion)
- non-polar hydrophobic tail (water hating, interacts with oil, dispersion forces)
what is a soap
a soap is an ion with a long non-polar alkyl tail and a polar charged carboxylate head (usually present in Na and K salts) (from natural oils and fats)
what is an anionic detergent
is an ion with a ion with a long non-polar alkyl tail and a polar anionic sulfate or benzenesulfonate head (usually present in Na and K salts) (too harsh for personal hygiene)
what is a cationic detergent
is an ion with a long non-polar alkyl tail and a polar cationic trimethylammonium or quaternary ammonium head (usually present in Cl or Br salts) (biocidal reduces static friction and tangling)
what is a non-anionic detergent
is a molecule with a long non-polar alkyl tail and a polar repeating uncharged polyethylene glycol head
- ends in an alcohol group
in presence of a non-polar substance the action of surfactants on the water
- hydrophilic head in water and hydrophobic tail sticking out in a line
- dissolve to form spherical micelles (repel each other) with head outside and tail inside
- if non-polar substances are stuck onto a surface:
1. surfactant dissolves in water
2. monolayer formation in grease
3. agitation separates grease from surface
4. micellisation and emulsifica
what is hard water
is impure water which contains >20ppm of Ca2+ or Mg2+ ions
- soaps struggle (carboxylate ion precipitates with the 2 ions to form a solid called scum
- anionic detergents struggle (form soluble complexes with the 2 ions although phosphate builders can precipitate with the ions)
- neutral non-anionic detergents are not affected (don’t react with Ca2+ and Mg2+)
what are polymers
are molecules which are composed of many identical, repeating subunits known of monomers
- can be formed through addition polymerisation or condensation polymerisation
- total addition of all monomers is the total mass of the polymer
what is polyethylene (polyethene)
ethene (ethylene) is important feedback to produce addition polymers
- ethene are monomers
- 2 types of polyethylene (LDPE, HDPE)
low density polyethylene (LDPE)
is characterised by extensive chain branching and low density formed at high temperature and pressure
- chemically unreactive (saturated hydrocarbon)
- soft and flexible (not tightly packed)
- transparent (low degree of light scattering)
- low melting point (weak dispersion forces)
- used for plastic shopping bags
high density polyethylene (HDPE)
is characterised by minimal chain branching and long linear polymer molecules and formed at low temperature and pressure and with Zieglar-Natta catalyst.
- chemically unreactive (saturated hydrocarbon)
- highly rigid (tight packing, strong dispersion forces)
- opaque (high light scattering)
- high BP/MP
- used for chairs
what is a polyvinyl chloride
polyvinyl chloride (polychloroethene, PVC) is an addition polymer from chloroethene monomers (vinyl chloride)
- are stiffer than polyethylene (Cl>H)
- held together by stronger dipole dipole and dispersion forces (Cl>H)
- brittle
- PVC + UV absorber prevents sun degradation,
- PVC + heat stabiliser improves performance at high temperatures
- PVC + plasticer softens
- used for banks cards, water pipes
what is polystyrene
polystyrene (polyethenylbenzene, PS) is an addition polymer produced from styrene (ethenylbenzene) monomers
- are 2 forms: crystal and expanded
crystal polystyrene
- rigid (stiffness from bulky benzene rings)
- brittle
- transparent (low light scattering)
- 100C deforming temperature
- used for CD cases
expanded polystyrene
- comprehensible and lightweight (N2 gas pockets)
- maintains shape
- heat and sound insulation (N2 gas pockets)
- opaque (high light scattering)
- used for packaging material
what is polytetrafluoroethylene
polytetrafluoroethylene (polytetrafluoroethene, PTFE) is an addition polymer produced from tetrafluoroethylene (tetrafluoroethene) monomers
- rigid and durable (H<F<Cl)
- chemically unreactive (C-F is strongest carbon bond)
- high BP
- hydrophobic (non-polar)
- lipophobic = non stick and low friction (weak dispersion forces)
- used for non stick frypans
determining structure of addition polymer from monomer
- identify double or triple bond
- redraw monomer to make the double or triple bond central
- bond individual monomers to the carbon atoms involved in double/triple bonds
- all other atoms are side chains
what is a condensation polymer
is the formation of polymers via repeated condensation reactions while eliminating a small molecular product (usually water or ammonia)
- polyamides, nylon, proteins and polyesters are formed using condensation
what is a polyamide
is formed by the repeated condensation reaction of dicarboxylic acid and diamine co-monomers
what is nylon
synthetic linear polyamide and type of condensation polymer
- the most common is nylon-6,6 made from hexane-1, 6-diamine and hexanedioic acid co-monomers
- high tensile strengnth
- rigid
- resistant to chemical and thermal degredation
- used for car engines
what is a protein
a natural polyamide and condensation polymer characterised by repeating ester units produced from dicarboxylic acid and diol co-monomers
- most common is PET (polyethylene terephthalate) made from ethane-1,2-diol and benzene-1, 4-dioic acid monomers
- strong polar ester linkage
- rigid (benzene rings)
- colourless
- high tensile strength and MP
- semi-crystalline and water resistant
- used for heavy duty fabrics
chemical structure of all polymers
- increase chain length = increase dispersion forces and rigidity and BP
- increase in crystalline (opposite is amorphous) = increase in intermolecular force strength and density/rigidity and BP
- chain branching = loose packing and amorphous molecules
- chain stiffening from large side chains = increase rigidity
biodegradability of all polymers
- increase in polarity of bonds = increase in biodegradability
- increase in CH bonds
- C-Cl, C=O, C-N, C-O are easier to biodegrade
- condensation polymers are easier to biodegrade than addition polymers
primary amide functional group trend
- increase chain length doesn’t increase BP
- H-bond and polar therefore high BP
- soluble in water and solids at 25C
carboxylic acid functional group trend
- H-bond and polar therefore high BP
- soluble in water
primary alcohols functional group trend
- H-bond and polar therefore high BP
- H in OH group is donor and 2 lone O pairs
primary amines functional group trend
- H-bond and polar therefore high BP
- 2 H’s of amines are donors and 1 lone N2 pair
- due to trigonal pyramidal geometry, doesn’t stack well, decrease reaction efficiency
- low BP
- soluble in water
aldehydes and ketones functional group trend
- polar bonds
- increase symmetry = increase reaction efficiency
- increase chain length = decrease in water solubility
esters functional group trend
- polar bonds
hydrocarbons functional group trend
- only dispersion forces
- low BP
- insoluble in water
what is polyster
a condensation polymer characterised by repeating ester units. they are produced by dicarboxylic acid and diol co-monomer
- most common is PET (polythyleneterephthalate)
PET
formed from condensation reaction between ethane-1,2-diol and benzene-1,4-dioic acid monomers
- ester linkage is polar due to polar C-O and C=O bonds
- benzene rings give PET rigidity
- properties (colourless, high tensile strength from polar bond, high MP, semi-crystalline, water resistance)
