Module Seven - Organic Chemistry Flashcards
Nomenclature Hydrocarbons Products of Reactions Involving Hydrocarbons Alcohols Reactions of Organic Acids and Bases Polymers
how many types of carbon bonds are there?
3 (single, double, triple)
what are the first eight prefixes in naming alkanes/alkenes/alkynes?
1: meth-
2: eth-
3: prop-
4: but-
5: pent-
6: hex-
7: hept-
8: oct-
what determines that a compound is an alkane?
only has single bonds
what determines that a compound is an alkene?
has at least one double bond
what determines that a compound is an alkyne?
has at least one triple bond
what is the general formula for alkane?
CnH(2n+2)
can alkanes be both straight-chained and branched?
yes
what are the two types of alkanes (structure-wise)?
- straight-chained
- branched
what is the prefix of a based on when naming a compound?
the longest chain in the compound (parent chain)
how are substituents ordered when naming a compound?
in alphabetical order
what is the purpose of the numbers before the substituents when naming a compound?
shows the position of the substituent on the parent chain
which end do you start counting from when naming a compound?
- the end with the more significant section of the compound (functional group)
- smallest addition of substituent positions
what is the general formula for alkene?
CnH2n
what is the general formula for alkyne?
CnH(2n-2)
how is the position of a bond named in an alkyne/alkene?
by putting the number position in front of the name
e.g. 2-butyne
what are halogenated organic compounds?
compounds where a hydrogen/s is replaced with a halogen (haloalkanes)
how are halogens included when naming halogenated organic compounds?
- similar to substituents
- -ine is replaced with -o
- if appeared multiple times, write all positions
- alphabetical order
what are a few halogens?
fluorine, bromine, iodine, chlorine
what are isomers?
same molecular formula but different structure
what are the three types of structural isomers?
chain, functional group, position
what are a few uses of alkanes?
- methane: main component of natural gas
- propane: liquid petroleum gas
can hydrocarbons conduct electricity?
no
why can’t hydrocarbons conduct electricity?
lack of dipole or ionic charges
are hydrocarbons soluble in water?
no
why aren’t hydrocarbons soluble in water?
they are non-polar
can hydrocarbons dissolve in non-polar substances?
yes!!!
why can hydrocarbons only be dissolved in non-polar substances?
like dissolves like babey
do hydrocarbons have low melting and boiling point?
yes
why are hydrocarbons have low melting and boiling point?
formation of weak dispersion forces between molecules
what are chain isomers?
- same molecular formula
- the length in parent chain is different
what are functional group isomers?
- same molecular formula
- different functional groups
what are position isomers?
- same molecular formula
- probably same parent chain length
- positions of substituents are different
what are functional groups?
particular groups of atoms that allow for ‘families’ of organic compounds to share similar chemical properties
what are homologous series?
series or ‘families’ of compounds with different functional groups
what functional group belongs to alcohol?
hydroxyl group (-OH)
what functional group shows aldehyde?
double bonded O in last carbon
what functional group shows a ketone?
double bonded O on a middle carbon
what functional group shows a carboxylic acid?
double bonded O and hydroxyl (-OH) on last carbon
what functional group shows an ester?
double bonded O, single-bonded O, with an R chain
what functional group shows an amine?
-NH2
what functional group shows an amide?
double bonded O with NH2 on last carbon
what is the suffix for a haloalkane?
-ane
what is the suffix for alcohols?
-ol
what is the suffix for aldehydes?
-al
what is the suffix for ketones?
-one
what is the suffix for carboxylic acids?
-oic acid
what is the suffix for esters?
alkyl -oate
what is the suffix for amines?
-amine
what is the suffix for amides?
-amide
what is an example of a haloalkane?
bromoethane
what is an example of an alcohol?
ethanol
what is an example of an aldehyde?
propanal
what is an example of a ketone?
propanone
what is an example of a carboxylic acid?
ethanoic acid
what is an example of an ester?
methyl ethanoate
what is an example of an amine?
ethanamine
what is an example of an amide?
methanamide
what are a few uses of alcohol?
- beverages
- additive to petrol
- solvent in medicine
what is the general formula for alcohol?
CnH(2n+1)OH
what are the three types of alcohols?
- primary (1°)
- secondary (2°)
- tertiary (3°)
what is a primary alcohol?
one carbon atom is bonded to the carbon atom with the -OH
what is a secondary alcohol?
two carbon atoms are connected to the carbon atom with -OH
what is a tertiary alcohol?
three carbon atoms are connected to the carbon atom with -OH
what are the two factors that affect the properties of alcohols (boiling point and solubility)?
- presence of the -OH group
- size of the hydrocarbon chain
do alcohols have a higher boiling point than alkanes/alkenes/alkynes?
yes
why do alcohols have a higher boiling point than alkanes/alkenes/alkynes?
- presence of -OH
- -OH can make hydrogen bonds between other -OH of the alcohol molecules
- strength of hydrogen bonds is much greater than weak dispersion forces
is solubility of alcohols affected by the ratio between the polar -OH and non-polar hydrocarbon section?
yes
how is solubility of alcohols affected by the ratio between the polar -OH and non-polar hydrocarbon section?
- small alcohols: effect of polar -OH group outweighs the non-polar hydrocarbon (very soluble)
- larger alcohols: effect of the non-polar section outweighs the polar functional group (insoluble)
why are some larger alcohol soluble in water?
may have multiple hydroxyl groups that multiply the polarity
what is an example of a large soluble alcohol molecule?
glucose (5 hydroxyl groups!!!)
is the hydroxyl group polar?
yes
does chain length affect solubility in alcohols?
yes
what are the two main types of carbonyl compounds?
aldehydes + ketones
what is the difference between a ketone and aldehyde?
the double bond in aldehydes are at the end of the chain, while ketones are in the middle
what is an example of a functional group isomer?
aldehyde and ketones
what are dipole-dipole bonds?
attractive forces between the positive end of one polar molecule and the negative end of another polar molecule
do aldehydes and ketones have higher boiling points than hydrocarbons?
yes
why do aldehydes and ketones have higher boiling points than hydrocarbons?
dipole-dipole bonds
do aldehydes and ketones have higher boiling points than alcohols?
no
why do aldehydes and ketones have lower boiling points than alcohols?
hydrogen bonds are stronger than dipole-dipole bonds
are aldehydes and ketones more soluble than hydrocarbons?
yes
why are aldehydes and ketones more soluble than hydrocarbons?
the carbonyl group is highly polar
are aldehydes and ketones more soluble than alcohols?
no
why are aldehydes and ketones less soluble than alcohols?
hydroxyl group is more polar than carbonyl group
does chain length affect solubility of aldehydes and ketones?
yes
how does chain length affect aldehyde and ketone solubility in water?
as chain length increases, solubility decreases (non-polar outweighs polar)
what is the general formula of aldehydes?
RCHO
what is the general formula of ketones?
RCOR’
what is the general formula for carboxylic acids?
CnH(2n+1)COOH
what is the common name for acetic acid?
vinegar
what functional group contains are carboxyl group?
carboxylic acid
what is a carboxyl group?
contains a carbonyl (C=O) and hydroxyl (-OH) together
what is another name for ethanoic acid?
acetic acid (CH3COOH)
do carboxylic acids have a higher boiling point than hydrocarbons?
yes
do carboxylic acids have a higher boiling point than alcohols?
yes
do carboxylic acids have a higher boiling point than aldehydes and ketones?
yes
why do carboxylic acids have a higher boiling point than hydrocarbons, alcohols and aldehydes/ketones?
as two carboxylic acid molecules can form TWO hydrogen bonds with one another
does chain length affect the solubility of carboxylic acids?
yes (larger = less soluble)
are carboxylic acids weak or strong?
weak
what type of acids are carboxylic acids?
weak monoprotic acids
what is a monoprotic acid?
acid donates only one proton or hydrogen atom per molecule to an aqueous solution
are carboxylic acids soluble in water?
small carb acids are soluble
how are carboxylic acids soluble in water?
the carboxyl group forms h-bonds with the water
what does it mean when an acid is weak?
will only partially ionise in water
how is an amide formed from an amine?
amine + carboxylic acid –> amide
what is the general formula for amines?
RNH2
what are the three types of amines?
primary, secondary, teritary
what is a primary amine?
has one alkyl group attached to the nitrogen
what is a secondary amine?
has two alkyl groups attached to the nitrogen
what is a tertiary amine?
has three alkyl groups attached to the nitrogen
are amines polar?
yes
how are amines polar?
nitrogen is very electronegative (NH2 is very polar)
why can’t tertiary amines form hydrogen bonds?
there are no hydrogens connected to the nitrogen in a teritary amine
do amines have a higher a boiling point than alcohols?
no
why do amines have a lower a boiling point than alcohols?
nitrogen is less electronegative than oxygen
are amines soluble in water?
yes (small primary and secondary)
why are amines soluble in water?
hydrogen bonding
are tertiary amines soluble?
no
why are tertiary amines insoluble?
lack a N-H bond to create h-bonds with the water
why is the boiling points of tertiary amines lower than primary and secondary amines?
lacks a N-H bond, so therefore cannot form hydrogen bonds
from what functional group are amides derived from?
carboxylic acids
how are amides derived from carboxylic acids?
when the -OH of the carb acid is replaced by -NH2 (amine)
what structural unit do all amides have?
-CO-NH-
how many types of amides are there?
three
what are the three types of amides?
primary, secondary, tertiary
what is a primary amide?
only one alkyl group attached to the -CO-NH-
what is a secondary amide?
has two alkyl groups attached to the -CO-NH-
what is a tertiary amide?
has three alkyl groups attached to the -CO-NH-
what is the genral formula of amides?
RCONHR’
is the boiling point of a tertiary amide lower than primary and seconday amide?
yes
why is the boiling point of a tertiary amide lower than primary and seconday amide?
has no N-H bond to form hydrogen bonding
why do amides generally have a high melting-boiling point and solubility?
has two polar bonds to create strong intermolecular bonds
what are the three ways an organic compound can enter the body?
inhalation, absorption, and ingestion
what is the effect of inhaling an organic compound?
organic compound will dissolve in the blood through the lungs and travel throughout the body, where it can accumulate
what is the effect of absorbing an organic compound through the skin?
the compound will dissolve through the skin and enter the bloodstream and travel throughout the body, accumulating inside organs
what is the effect of ingesting an organic compound?
the organic compound will be dissolved in the stomach, entering the bloodstream, and travel around the body, accumulating in organs
what are the hazardous physical properties of organic compounds?
volatility, flash point
what does volatile mean?
easily evaporated in regular temperatures
are most organic compounds volatile?
yes
why are compounds being volatile dangerous?
colourless vapours can fill the room and be inhaled
what makes an organic compound volatile?
weak intermolecular forces
what does flashpoint mean?
degree of flammability (lowest temperature a compound can be at before being ignited)
what are a few symptoms of skin contact with dangerous organic compounds?
burning or tingling, rashes, welts, chemical burns
what are the two levels of organic chemical poisoning?
acute, chronic
what are the symptoms of acute organic compound poisoning?
headaches, dizziness, affected reaction time and vision, poor coordination
what are the symptoms of chronic organic compound poisoning?
fatigue, physical weakness, mood swings, liver/kidney damage
how does one end up suffering from chronic organic compound poisoning?
after repeated exposure of years
what are the methods of prevention in the safety of using organic compounds?
minimisation, isolation, ventilation
how does minimisation help prevent organic compound poisoning?
by reducing (minimising) the use of particular dangerous compounds
how does isolation help prevent organic compound poisoning?
physical separation from chemicals can reduce exposure significantly
what are a few examples of small-scale isolation when handling organic compounds?
lab coat, goggles, gloves
how does ventilation help prevent organic compound poisoning?
draws fumes away from the user
what are the two levels of ventilation when handling organic compounds?
small-scale, large-scale
what does small-scale ventilation include when handling organic compounds?
fume cupboard that will draw fumes upwards and away from the user
what does large-scale ventilation include when handling organic compounds?
giant extractor systems that clear room and factory vapours
who deals with organic waste?
chemical waste disposal companies
what is the main disposal rule when handling organic compounds?
to not wash down the sink
why is it inappropriate to wash organic compounds down the sink?
chemicals will accumulate in sewer systems, and thus into our water ways, which’ll poison aquatic life
what are the methods used by larger companies when dealing with organic waste?
- neutralisation: removal of acid and base
- filtration: removal of solid particles
are double and triple carbon bonds weaker than single carbon bonds?
no, they are stronger
are alkenes and alkynes more reactive than alkanes?
yes
can alkenes and alkynes undergo combustion?
yes
what is combustion?
substances are burnt in the presence of oxygen, releasing energy
what are the two types of combustion?
complete and incomplete
what makes the difference between complete and incomplete combustion?
- the amount of oxygen present
- production of carbon/carbon monoxide
what is an addition reaction
the addition of atoms by breaking the double or triple bond
what substances can be reacted with an alkene/alkyne in an addition reaction?
- hydrogen (H2)
- water (H2O)
- hydrogen halides (HX)
- halogens (X2)
what hydrocarbons can undergo addition reactions?
alkenes and alkynes
what is the addition of hydrogen in an addition reaction?
hydrogenation
what is hydrogenation?
the addition of hydrogen to an alkene/alkyne in an addition reaction
what are alkenes converted to in an addition reaction?
alkanes
what is required in the process of hydrogenation?
metal catalyst
are alkenes unsaturated or saturated?
unsaturated
are alkynes unsaturated or saturated?
unsaturated
what are alkynes converted to in an addition reaction?
alkenes
what is the addition of halogens called in an addition reaction?
halogenation
what is halogenation?
the addition of halogens to an alkene/alkyne in an addition reaction
what is a hydrogen halide?
molecule with a hydrogen atom and halogen atom
what are a few examples of hydrogen halides?
hydrogen chloride, hydrogen bromide
what is the addition of water called in an addition reaction?
hydration
what is hydration in an addition reaction?
the addition of water to an alkene/alkyne in an addition reaction
what substance is required for water to be added to an alkene/alkyne in an addition reaction?
dilute sulfuric acid catalyst
what is a popular chemical that is produced through hydration (addition reaction)?
ethanol
what will be produced through the hydration of an alkyne?
ketone
what are the two reactions involving saturated hydrocarbons?
combustion, substitution with halogens
can all hydrocarbons undergo combustion?
yes!
what is required for alkanes to undergo halogen substituion?
UV light
what is produced when alkanes under halogen substitution?
haloalkanes
what does halogen substitution in alkanes include?
a halogen atom substitutes for a hydrogen atom
what two elements is optimal for halogen substitution in alkanes?
chlorine and bromine
why is UV light required in halogen substitution in alkanes?
will not occur unless sufficient amounts of energy is supplied
what is a qualitative experiment that models halogen substitution?
bromine water experiment
what does the bromine water test tell us?
allows us to distinguish between a alkane and alkene
- alkene: brown –> colourless
- alkane: brown –> brown
how does the bromine water test work?
under UV light, the alkene double bond will break open and react with the bromine, discolouring the water, making it colourless
what is a halogen substitution example?
methane + bromine –> bromomethane + hydrogen bromine
CH4(g) + Br2(aq) –> CH3Br(aq) + HBr(g)
where are hydrocarbon primarily sourced from?
crude oil, natural gas
what is crude oil?
a mixture of hydrocarbons
how is crude oil processed to make hydrocarbons?
fractional distillation
what does fractional distillation do?
seperate substances with different boiling points
how does fractional distillation work?
- crude oil is heated at the bottom of the tower
- the gases rise up each column (high heat –> low heat)
- whenever a substance gets below its boiling point, it will condense into a liquid
- substance is then extracted through the multiple exits of the tower
what is the order of condensation of substances in fractional distillation?
highest boiling point –> lowest boiling point
what is a potential environmental impact of mining and transporting oil and gas?
possible contamination of habitats in the case of oil spills during transport
what is a potential economic impact of mining and transporting oil and gas?
loss in jobs in tourism and fishing industry due to depletion of fish stocks due to disruption of habitat
what is a potential sociocultural impact of mining and transporting oil and gas?
psychological stress due to job loss and mortgage stress
what is the greenhouse effect?
the trapping of the sun’s warmth in the Earth’s atmosphere due to being absorbed by greenhouse gases
how is the use of hydrocarbons related to the greenhouse effect?
CO2 from fossil fuel combustion is considered a greenhouse gas, which traps in heat
how does carbon dioxide result in a rise in global temperature?
CO2 absorbs infrared radiation
what are a few consequences of the greenhouse effect?
- melting ice caps
- global warming
- climate change
- affected ice formation
- rising sea levels
how does using fossil fuels lead to more acidic oceans?
CO2 from fossil fuel combustion is absorbed in the sea, making it acidic
what are the equations related to the acidifying of the ocean due to CO2?
CO2(aq) + H2O(l) ⇌ H2CO3(aq)
H2CO3(aq) + H2O(l) ⇌ H3O+(aq) + HCO3-(aq)
what is the largest impact of decreasing pH of the ocean?
death of coral reefs
how do polymers cause waste?
- made of hydrocarbons
- causes environmental impacts
- pollution and waste
what is enthalpy of combustion?
heat energy that is released when 1 mole of fuel is combusted
what is the formula for quantity of heat?
q = mc∆T
what is enthalpy?
measure of total energy possessed by a substance
how do you calculate change in enthalpy?
∆H= -q/n
is the change in enthalpy always negative in combustion?
yes
why is the change in enthalpy always negative in combustion?
heat is released, so the internal energy of the substance decreases
what is the purpose of calorimetric experiments?
measure the enthalpy of combustion of alcohols (fuels)
what does it mean when an alcohol is dehydrated?
loss of water to form alkenes
what substance/s is required to dehydrate alcohol?
- concentrated H2SO4
- phosphoric acids
what is an example of the dehydration of an alcohol?
2- butanol –> 1-butene + H2O
how is an alkyl halide formed?
alcohol + hydrogen halide
what is the general reaction for the substitution of hydrogen halides (HX) in alcohols?
R-OH + H-X –> R-X + H2O
what is formed when an alcohol is reacted with a hydrogen halide?
alkyl halide
what is an example of hydrogen halides substitution in alcohols?
2-methyl-2-propanol + HCl –> 2-chloro-2-methylpropane +H2O
which type of alcohol reacts the quickest with hydrogen halides?
tertiary alcohols
why do tertiary alcohols react the fastest with hydrogen halides?
it is the most reactive out of the three types of alcohol
which hydrogen halide is the most reactive?
hydrogen iodide (HI)
which hydrogen halide is the least reactive?
hydrogen fluoride (HF)
what is the trend of reactivity for hydrogen halides on the periodic table?
reactivity increases down the halogen group
what are the types of reactions with alcohol?
- dehydration
- combustion
- hydrogen halide substitution
- oxidation
can all types of alcohols be oxidised?
only primary and secondary
what are the two oxidising agents used in alcohol oxidation?
- acidified permanganate ion (MnO4-)
- dichromate ion [Cr2O7(2-)]
what is formed through the oxidation of primary alcohols?
aldehydes
what is an example of the oxidation of a primary alcohol?
ethanol –> ethanal
what are the two steps of oxidising a primary alcohol?
alcohol –> aldehyde –> carboxylic acid
what oxidising agent is used to oxidise a primary alcohol?
dichromate ion [Cr2O7(2-)]
what is the colour change when a primary alcohol is oxidised?
orange –> green
what is the colour change when a secondary alcohol is oxidised?
purple/pink –> brown/colourless
is there a second stage when oxidising a secondary alcohol?
no
what substance can be used to oxidise secondary alcohols?
- acidified permanganate ion (MnO4-)
- dichromate ion [Cr2O7(2-)]
what is an example of a secondary alcohol oxidisation?
2-propanol –> propanone
what is the colour change when a tertiary alcohol is oxidised?
no colour change, as it cannot be oxidised
what causes the colour change in the oxidisation of the alcohol?
the alcohol does not change colour, but the oxidising agent does
what are the three methods used in producing alochols?
- from alkenes
- from halogenated organic compounds
- fermentation
how are alcohols produced from alkenes?
water + alkene
- in the presence of H2SO4
what is an example of an alcohol being produced from an alkene?
1-butene + H2O –> 2-butanol
how are alcohols produced from halogenated organic compounds?
water + haloalkane
what type of reaction is the production of alcohol from halogenated organic compounds?
substitution reaction
- halogen atom is replaced by -OH
what is an example of an alcohol being produced from a halogenated organic compound?
2-bromobutane + H2O –> 2-butanol
why are haloalkanes more likely to undergo substitution reactions than non-halogenated alkanes?
C-halogen is easier to break than C-C or C-H
what is bond energy?
the amount of energy required to break a chemical bond
why can’t fluoroalkanes undergo reaction with water to form alcohols?
C-F bond too hard to break
how many different types of haloalkanes are there?
3
what are the different types of haloalkanes?
primary, secondary, tertiary
how are alcohols produced through fermentation?
break down of sugars by yeast to produce alcohols in an anaerobic environment
what is fermentation?
conversion of sugars to alcohols in an anaerobic environment
e.g. glucose –> ethanol
what substance is significant in the process of fermentation?
yeast
what is the role of yeast in fermentation?
yeast will produce ethanol as a by-product from processing glucose
what are the different types of sugars?
- monosaccharides
- disaccharides
- polysaccharides
which type of sugar is the most simple?
monosaccharides
what are examples of monosaccharides?
glucose, fructose
what are monosaccharides?
simple sugars consisting of single ring structures with 4-6 carbons
what are disaccharides?
consists of two carbon rings
how are disaccharides produced from monosaccharides?
two monosaccharides undergo a condensation reaction to produce disaccharides
what is an example of a dissacharide?
sucrose
what are polysaccharides?
multiple monosaccharides and disaccharides joined together
what are examples of polysaccharides?
cellulose, starch
which type of sugar is yeast most efficient at breaking down?
monosaccharides
how are monosaccharides produced from disaccharides?
hydrolysis
what conditions are required fro fermentation?
- low temperature (~33˚C)
- slightly acidic (6.1-6.8)
- anaerobic environment
why must the conditions be met for fermentation?
if not met, the enzymes will denature, and thus will not produce alcohol
what are the two main types of fuel?
fossil fuels and biofuels
what are the two types of biofuels?
- ethanol
- biodiesel
what type of fuel is primarily used?
fossil fuels
what are fossil fuels?
decayed animal and plant matter
what are biofuels?
produced from renewable resources
what are some examples of fossil fuels?
coal, crude oil and natural gas
why is the combustion of fossil fuels bad?
greenhouse effect from produced CO2
why are biofuels considered renewable?
can be continuously produced from crops, algae or animal waste
what are biodiesels made of?
fats and oils
what is process of making biodiesel called?
transesterification
what is a disadvantage of biofuels?
- cost
- vehicle modifications
what is the ester functional group?
O=C-O
what is the general formula for an ester?
R-C=O-O-R’
what is a physical property that can help identify an ester?
pleasant fruity smell
what is the main use of esters in the industry?
artificial flavouring
what is an ester link?
the functional group part of an ester
how are esters made?
carboxylic acid + alcohol –> ester
how are esters named?
- alkyl comes from the alcohol - the part with the single bonded oxygen (-anol to -yl)
- second part comes from the acid - the part with the double bonded oxygen (-ioc acid to - oate)
e. g. propanol + methanoic acid –> propyl methanoate
what is a functional group isomer of esters?
carboxylic acid
are esters polar?
yes
why are esters polar?
presence of C-O and C=O
do esters have a higher or lower boiling point than carboxylic acids?
lower
why do esters have a lower boiling point than carboxylic acids?
main intermolecular force is dipole-dipole
are esters highly soluble in water?
no
why aren’t esters soluble in water?
- lack of hydrogen bonding
- presence of large hydrophobic alkyl groups
what substances are esters soluble in?
organic solvents
what type of reaction is esterification?
condensation
what is produced in esterification?
ester + water
what are the conditions for esterification?
- requires a catalyst (conc. H2SO4)
- high temperatures
what type of equipment is required for esterification?
reflux apparatus
what is the reflux process?
reactants are heated for an extended amount of time without the loss of any reactants and products
how is there no loss of substances during esterification?
all evaporated gaseous substances are cooled down in the vertical condenser
how can the yield in esterification be increased?
adding a reagent in excess to push the reaction towards the product side
why is it required to purify an ester after refluxing?
flask will contain both organic and inorganic substances
- organic: ester, carb acid, alcohol
- inorganic: water, sulfuric acid
what piece of equipment is used to purify an ester?
separating funnel
what is the purpose of a separating funnel?
separates immiscible liquids according to density
- low density at the top
- high density at the bottom
what steps are included in purification of an ester?
- washing with water
- addition of sodium carbonate
- distillation
what is the purpose of washing the ester with water during ester purification?
removes water soluble substances
- put in a separating funnel
- organic substances will rise to the top
- leaves ester in top layer
- bottom layer can be separated
what is the purpose of washing the ester with water during ester purification?
remove any carboxylic acid
what is the purpose of washing the ester with water during ester purification?
isolate the ester from other contaminants
what is the most common organic acid?
carboxylic acid
what do organic acids include?
- straight chain carboxylic acids
- more complex acids
what are a few examples of organic acids?
methanoic acids, ethanoic acid, citric acid
what is a common organic base?
amines
what are organic bases based on?
nitrogen compounds (amines)
do organic and inorganic acids and bases react similarly?
yes
are organic acids generally weak or strong?
weak
do organic acids usually have a low or not so low pH?
not so low
what can organic acids react with?
active metals, bases and carbonates
what is produced in the reaction between organic bases and acids?
a protonated amine
what are the three types of detergent?
anionic, cationic, non-ionic
what does dissolving soap in water do?
lowers surface tension
what is the purpose of a surfactant?
lowers surface tension of water
how does a surfactant lower surface tension of water?
breaks h-bonds between the water molecules, spreading them out
what are the two important properties of soaps and detergents?
- surfactant
- emulsifier
what is an emulsifier?
can cause two immiscible liquids to mix, causing an emulsion
what does immiscible liquids mean?
unable to mix together
how are soaps related to fatty acids?
soaps are salts of fatty acids
what do soaps consist of?
- long hydrophobic hydrocarbon tail
- hydrophilic head (carboxylate ion)
what makes the head of a soap molecule hydrophulic?
it is polar due to the carboxylate ion
what are anionic detergents?
have a negatively charged ion attracted to the head
e.g. Na+
what are cationic detergents?
have a positively charged ion attracted to the head
e.g. Cl-
what are non-ionic detergents?
have no ionic charge
what are a few uses of anionic detergents?
- laundry detergent
- dishwashing detrgent
- household cleaners
what are a few uses of cationic detergents?
- fabric softeners
- hair conditioners
- disinfectants
- sanitisers
what are a few uses of non-ionic detergents?
- dishwasher detergents
- glass cleaners
what are a few characteristics of anionic detergents?
- good lather
- negative charge
- harsh
- cheap
what are a few characteristics of cationic detergents?
- bond strongly to negatively charged surfaces
- reduces static and friction
- biocidal (kills bacteria)
- expensive
what are a few characteristics of non-ionic detergents?
- low lather (no foam build up)
- expensive
through what process are soaps made?
saponification
what are the reactants in saponification?
triglyceride + hydroxide
what is the general reaction of saponification?
fat (triglyceride) + hydroxide –> glycerol + fatty acid salts
what is done in the process of saponification?
- a fat/ oil is boiled with a hydroxide (e.g. NaOH)
- soap is curdled at the surface to be collected
- rest is precipitated at the addition of NaCl
what is salting out?
the addition of NaCl in saponification to precipitate out more soap
how do soaps and detergents work?
- soap is dissolved in the water
- hydrophobic tails is embedded into the grease, hydrophilic head sticking out (ionic head forms strong ion-dipole bonds with the water)
- grease is agitated, lifting grease molecules from the surface (water pulls through ion-dipole bonds)
- more soap molecules surround the grease particle
- micelle is formed
- micelles repel each other (negatively charges due to head) and form an emulsion
- rinsed off
how can soaps be made at home?
vegetable oil + sodium hydroxide
what do soaps form in hard water?
scum
do detergents form scum in hard water?
no
what is the appropriate cleaning substance is more appropriate to use in hard water?
detergents (no scum)
how is scum formed from soaps in hard water?
the cations (Ca2+ and Mg2+) bond with the carboxylate ions of soap to form a solid precipitate
what is hard water?
water that contains high levels of Ca2+ and Mg2+
how are carboxylate ions formed from carboxylic acids?
+CO3(2-)
how do alkenes form from alkynes?
hydrogenation (+X2)
how do alkanes form from alkenes?
hydrogenation (+H2)
how do haloalkanes form from alkanes?
substitution of X2 with UV light
X = halogen
how do alcohols form from alkenes?
dehydration (-H2O)
how do alkenes form from alcohols?
hydration (+H2O)
how do haloalkanes form from alkenes?
addition (+HX)
how do haloalkanes form from alkynes?
hydrogenation/halogenation (+HX/X2)
how do alcohols form from haloalkanes?
hydration (+H2O)
how do haloalkanes form from alcohols?
hydrogenation (+HX)
how do alcohols form from glucose/sugars?
fermentation
how do ketones form from alcohols?
oxidation of secondary alochols
how do esters form from alcohols?
addition of carboxylic acids
how do aldehydes form from alcohols?
oxidation of primary alcohols
how do carboxylic acids form from aldehydes?
oxidation
how do esters form from carboxylic acids?
addition of alcohol
how do amides form from carboxylic acids?
addition of amine
how are amides formed from alkenes?
alkenes –> alcohols –> aldehydes –> carboxylic acids –> amide
how are esters formed from alkanes?
alkanes –> haloalkanes –> alcohols –> esters
how are aldehydes formed from alkynes?
alkynes –> haloalkanes –> alcohols –> aldehydes
how are carboxylate ions formed from alcohols?
alcohols –> aldehydes –> carboxylic acids –> carboxylate ions
how are carboxylic acids formed from haloalkanes?
haloalkanes –> alcohols –> aldehydes –> carboxylic acids
how are amides formed from alkynes?
alkynes –> haloalkanes –> alcohol –> aldehydes –> carboxylic acids –> amides
how are carboxylate ions formed from glucose/sugars?
glucose/sugars –> alcohols –> aldehydes –> carboxylic acids –> carboxylate ions
how are haloalkanes formed from glucose/sugars?
glucose/sugars –> alcohols –> haloalkanes
how are alkenes formed from glucose/sugars?
glucose/sugars –> alcohols –> alkenes
how are carboxylic acids formed from alkynes?
alkynes –> haloalkanes –> alcohols –> aldehydes –> carboxylic acid
how are esters formed from haloalkanes?
haloalkanes –> alcohols –> esters
how are aldehydes formed from glucose/sugars?
glucose/sugars –> alcohols –> aldehydes
how are amides formed from alcohols?
alcohols –> aldehydes –> carboxylic acids –> amides
how are alcohols formed from alkynes?
alkynes –> haloalkanes –> alcohols
what are synthetic polymers also known as?
plastics
what are few concerns surrounding plastic use?
- plastic pollution
- depleting resources
what do polymers consist of?
monomers joined by covalent bonds
what are the two types of polymerisation?
addition and condensation
what are thermoplastic polymers?
- can soften and be remoulded
- easily recyclable
what are the different types of polymers?
- high density polyethylene (HDPE)
- low density polyethylene (LDPE)
- polypropylene (PP)
- polyvinyl chloride (PVC)
- polytetrafluoroethylene (PTFE)
- polystyrene (PS)
what are the two types of polyethylene?
- high density (HDPE)
- low density (LDPE)
what makes a polyethylene low density?
- branched chains
- weak bonding due to weaker dispersion forces b/w further apart chains
- amorphous (disordered)
what makes a polyethylene high density?
- linear chains
- stronger bonding due to closer dispersion forces b/w chains
- crystalline (ordered)
where is ethylene obtained from?
crude oil
how are addition polymers formed?
formed by adding together monomers without loss of any atoms
what are the molecule requirements for addition polymerisation to occur?
- the monomer must have C=C
- bond will open to allow new bonds to form
what monomer is polyethylene consisting of?
ethylene
what is the general formula for polyethylene?
n(CH2=CH2)
what is required to start up LDPE polymerisation?
an initiator
what conditions are required to form LDPE?
- high temperature (~300°C)
- higher pressures (1000-3000 atm)
why are the chains in LDPE branched?
some hydrogens are replaces by alkyl groups
what are the properties of LDPE?
- low density
- low melting point
- greater flexibility
- soft
- transparent
- impermeable to water
what conditions are required to form HDPE?
- low pressure (few atm)
- low temperature (~60°C)
what are the properties of HDPE?
- higher density
- high melting point
- less flexible
- opaque
- rigid
what are a few uses of LDPE?
- plastic bags
- plastic food wrap
- lamination for paper
- milk cartons
what are a few uses of HDPE?
- detergent bottles
- bottle caps
- 3D printer filament
- fuel tanks
what is the general formula of PTFE?
n(CF2=CF2)
what does the tetrafluoroethylene monomer consist of?
- 2 carbons (double bonded)
- 4 fluorines
what is the common name for PTFE?
teflon
is PTFE strong?
yes
why is PTFE strong?
- polar C-F bonds
- dipole-dipole interactions
- resistant to the formation of dispersion forces
what are a few uses of PTFE?
- coating on non-stick pan
- electrical insulation
- artificial body parts
what does PTFE stand for?
polytetrafluoroethylene
what does PVC stand for?
polyvinyl chloride
what is the general formula for PVC?
n(CH2=CH-Cl)
what is the monomer for PTFE called?
tetrafluroethylene
what is the monomer of PVC called?
vinyl chloride
what does the vinyl chloride monomer consist of?
- 2 carbons (double-bonded)
- 3 hydrogens
- 1 chloride
is PVC strong?
yes
why is PVC strong?
polar due to highly electronegative Cl
- dipole-dipole + dispersion forces b/w molecules
what are plasticisers?
small molecules inserted between each polymer chain, to move them further apart - making the intermolecular forces weaker
what is the purpose of plasticisers?
makes polymer more flexible
what is the most widely used polymer?
PVC
which polymer is the cheapest?
PVC
what does PS stand for?
polystyrene
what is the monomer of PS called?
styrene
how is styrene made from ethylene?
hydrogen replaces by benzene
what is the general formula for PS?
n(CH2=CH-benzene)
benzene = C6H6
is PS amorphous?
yes
how is PS amorphous?
the benzene sticking out of the chain makes them further apart - weaker intermolecular forces
why are the PS molecules non-polar?
symmetry of the phenyl ring
are the PS molecules polar?
no
what is the force holding PS molecules together?
dispersion forces
what are some physical properties of PS?
- clear
- hard
- brittle
- soft when heated
- rigid when cooled
what does PP stand for?
polypropylene
how many variations are there for the structure of PP?
three
why are there variations of the PP structure?
dependent on the orientation of the CH3 group
what are the three variations of PP structure?
- atactic
- syndiotactic
- isotactic
what is the atactic arrangement in PP structure?
-CH3 group is randomly placed
what is the result of atactic arrangement in PP structure?
- chains cannot lie close together
- weak forces
what is the syndiotactic arrangement in PP structure?
-CH3 groups alternate above and below the chain
what is the result of syndiotactic arrangement in PP structure?
- can pack somewhat closely
- fairly strong forces
what is the isotactic arrangement in PP structure?
-CH3 groups are all on the same side
what is the result of isotactic arrangement in PP structure?
- can pack very closely
- maximum strength in forces
what are the physical consequences of atactic arrangement in PP structure?
- softer polymer
- lower melting point
what are the physical consequences of syndiotactic arrangement in PP structure?
softer than isotactic, but tougher than atactic
what are the physical consequences of isotactic arrangement in PP structure?
- strong
- hard
- excellent resistance to stress & cracking
what is the order of strength in tactic, isotactic and syndiotactic arrangement of PP molecules? (weakest to strongest)
atactic, syndiotactic, isotactic
what are a few common uses of PP?
- carpets
- rope
- twine
what are a few common uses of PVC?
- electrical insulation
- garden hoses
- pipes
what are a few common uses of PS?
- foam packing material
- disposable drink cups
- hard CD discs
what are a few common uses of PTFE?
- high-grade insulation
- non-stick surfaces
what are the six important structural features in polymers?
- crystallinity
- branching
- chain length
- side groups
- cross-linking
- stability/biodegradability
how does crystallinity affect polymer properties?
- crystalline: closer together - strong intermolecular forces (more rigid, high melting point)
- amorphous: disordered, tangled chains - weaker intermolecular forces (more flexible, lower melting point)
how does branching affect polymer properties?
- little to no branching: pack closely together - crystalline (denser, less flexible)
- high branching: further apart - amorphous (more flexible)
how does chain length affect polymer properties?
- longer similar chain lengths: higher melting point, more rigid
- shorter chains: difficult to mould, will sag
how do side groups affect polymer properties?
- bigger side group: reduces flexibility (stiff)
how does cross-linking affect polymer properties?
- linear chains are linked together
- becomes more rigid
- forms strong covalent/ionic bonds
what is the importance of stability/biodegradability in polymers?
- C-C & C-H are strong: more stable
- C-Cl bonds are weaker: will break if exposed to UV light for extended periods of time
what are condensation polymers?
will condense out a small molecule during polymerisation
what are the two types of condensation polymers?
- polyester
- nylon
what are the two types of nylon?
- nylon-6
- nylon-6,6
what structural requirement is required of monomers to undergo condensation polymers?
must have functional groups at the end
what functional groups are suitable for condensation polymers?
- NH2
- OH
- COOH
- COCl
what are polyesters?
condensation polymers that are joined by an ester link (-COO)
what functional groups can be joined to form a polyester?
carboxylic acid: carboxyl (-COOH)
alcohol: hydroxyl (-OH)
what is an example of polyester?
polylactic acid
what is a use of polyester?
biodegradable surgical sutures
what are polyamides?
condensation polymers that are joined by an amide link (H-N-C=O)
what functional groups can be joined to form a polyamide?
amine (-NH2)
carboxyl (-COOH)
what is a natural polyamide?
proteins
what is the most commonly known synthetic polyamide?
nylon
what are a few uses of nylon?
- fabric fibres
- machine components
- domestic appliances
what is the angle between the bonds when there are four single bonds around the C atom?
109.5°
what is the angle between the bonds when there is one double and two single bonds around the C atom?
120°
what is the angle between the bonds when there are two double bonds around the C atom?
180°
what is the angle between the bonds when there is one triple and one single bond around the C atom?
180°
what is the geometrical arrangement of the bonds when there are four single bonds around the C atom?
tetrahedral
what is the geometrical arrangement of the bonds when there is one double and two single bonds around the C atom?
planar
what is the geometrical arrangement of the bonds when there are two double bonds around the C atom?
linear
what is the geometrical arrangement of the bonds when there is one triple and one single bond around the C atom?
linear