5.2 Organic II Flashcards
Acid rain
Due to acid like sulphfur dioxide/nitrogen oxide reacting with water vapour in clouds
Addition polymerisation
Reaction in which many small molecule monomers bond together
-> forms long chain polymer
Additional reaction
Two molecules combine to form a larger molecule
Alcohols
Organic compounds containing functional group -OH
Suffix ending -ol
E.g. propan-2-ol
How can alcohols be oxidised to carboxylic acids
Microbial oxidation or reacting with potassium dichromate(VI)
How can alcohols be formed from alleles
Reaction with steam and phosphoric acid catalyst
Alkanes
Most common hydrocarbon found in crude oil
CnH2n+2
Allende’s
Hydrocarbons with a double bond between two of the carbon atoms in their chain
-> unsaturated
Some polyesters are
Biodegradable
Carboxylic acids
Organic compounds with functional group -COOH
First four members of a homologous series of carboxylic acids
Methanoic acid, ethanoic acid, propanoic acid, butanoic acid
Catalytic cracking
Long chain hydrocarbons are heated at 600-700 degrees to turn them into a gas
Vapour is passed over a silica or alumina catalyst
Long chain molecules split apart on surface of catalyst
Combustion
Combustion of a hydrocarbon fuels releases energy
During combustion, carbon and hydrogen in fuels are oxidised
Complete combustion
Combustion carried out in sufficient oxygen
Products of complete combustion of hydrocarbon
Water and carbon dioxide
Condensation polymerisation
Reaction in which monomers join together and lose small molecules e.g. water
These reactions involve monomers with 2 functional groups
Cracking
Process that involves breaking down larger hydrocarbons to produce small and more useful molecules
-> done by steam cracking or catalytic cracking
Crude oil
Finite resource found in rocks -> mostly hydrocarbons
Displayed formula
Shows all bonds between every atom in compound
Empirical formula
Smallest whole number ratio of atoms of each element in compound
E.g. CH2 is empirical formula of C2H4
Ester
Product of condensation reaction between carboxylic acid and alcohol
Volatile compounds with distinct smells
What are esters used in
Perfume and flavourings
Esters functional group
-COO-
Fermentation
Chemical process by which molecules such as glucose are broken down anaerobically
- ethanol produced when sugar solutions are fermented using yeast
Fractional distillation
Used to separate mixture of liquids
- have different boiling points so can be separated into different fractions
Fuel
Substance which releases energy when burned
Homologous series
Series of compounds with same functional group and similar chemical properties
Incomplete combustion
Combustion which is carried out with insufficient oxygen
-> leads to production of carbon monoxide
Isomerism
Molecules with exactly same molecular formula but different arrangement of atoms
Microbial oxidation
Ethanol undergoes microbial oxidation to produce ethanoic acid
-> oxidisation of substance by microorganisms
Products of incomplete combustion
Carbon (soot)
Polyester
Category of polymers which contains the ester functional group in their main chain
-> formed by condensation reaction between a diol and dicarboxylic acid
Saturated hydrocarbons
Hydrocarbon compound containing only single bonds between carbon atoms
E.g. alkanes
Homologous
Similar properties and so react in similar ways
Shorter alkanes
More flammable and less viscous
Complete combustion equations
Fuel + oxygen —> carbon dioxide and water
Exothermic
Steam cracking
Long-chain hydrocarbons are heated to turn them into a gas.
The hydrocarbon vapour is then mixed with steam and heated to a very high temperature which caused them to split into smaller molecules.
Structural formula
A formula which shows the arrangement of atoms in the molecule of a compound but does not show all the bonds between them. E.g. CH,CH,COCH,
Characteristic of compounds in a homologous series
- same general formula
- same functional group
- similar reactions
- trend in physical properties
Making ethanol: fermentation
C6H1206 —yeast—> 2CH3CH2OH + 2CO2
- At 30 degrees
- Yeast is the catalyst so if conc of alcohol is above 12%-14% yeast dies
- batch process and anaerobic to prevent microbial oxidisation to ethanoic acid
Making ethanol: hydration of ethene
Addition reaction
- 300 degrees and react w/ steam (H20)
- 60-70 atm pressure
- phosphoric acid catalyst
- continuous process and uses ethene made from cracking
oxidisation of alcohols: microbial oxidisation bacteria
CH3CH2OH + 02 —> CH3 COOH (vinegar/ethanoic acid) + H20
oxidisation of alcohols: acidified potassium dichromate
Orange -> greeen
CH3CH20H + 02 —>
Oxygen in air would react with ethanol and form ethanoic acid
Ethanol will burn in air, name products of reaction and equation
C2H5OH + 3O2 —> 2CO2 + 3H2O
Ethanol can be oxidised to ethanoic acid, name chemicals required
Potassium dichromate and dilute sulphuric acid
Batch processes
- rate of ethanol produced in slower
- less pure
- less use of finite resources (uses renewable)
Continuous process
- rate of ethanol produced in faster
- more pure
- more finite resources used
Reaction of carboxylic acids
Like acids -> released H+ when dissolved in water
Product formed when magnesium is placed in propanoic acid
Magnesium propanate
+ effervescence
Ethanoic acid common name
Vinegar
Increased concentration of particles means that
More frequency collisions and reaction rate with be greater
H2S04
Sulphuric acid
Fermentation advantages
Uses lower pressure and temperature which means energy costs are lower than hydrating
-> batch process
Ethanol chemical equation
C2H5OH
Why is fermentation done in absence of air
Oxygen in air would react with ethanol and form ethanoic acid common
Disposal of polymers
- sort and recycle
- incinerate in power stations
Halogen + alkane —(UV) —>
Halogenoalkane + hydrogen halide
Alkenes with bromine water vs alkanes
Alkenes - orange to colourless
Alkanes - remains orange
