Organic Chemistry Flashcards
What is organic chemistry.
The chemistry of carbon containing compounds.
How many and what type of bonds does carbon always have.
4 covalent
Write the starting names of the first 6 organic substances.
Meth Eth Prop But Pent Hex
What type of bonds do alkanes have and what does this make them.
All saturated single bonds.
What is the IUPAC nomenclature ?
The rules of how to name compounds worldwide.
What is a homologous series ?
A series of organic molecules whose general molecular formula are the same and they have the same basic structure which gives th similar chemical properties.
What is a functional group ?
A characteristic group that gives an organic molecules it’s chemical properties.
What is the general formula for alkanes ?
CnH2n+2
What are alkanes ?
A homologous series of hydrocarbons which are saturated and contain only single carbon-carbon bonds.
What is the definition of molecular formula ?
The actual number of each type of atom in a molecule.
What is the definition of empirical formula ?
The simplest whole number ratio of the atoms in a molecule.
What is structural formula ?
A formula showing how atoms are connected together in a molecules but most of the covalent bonds are not shown.
What is displayed formula ?
A formula showing how the atoms are separately arranged in a molecule.
What is skeletal formula ?
A simplified display formula where only carbon-carbon bonds and others key features are shown.
Revise naming branches alkanes.
In booklet
What are haloalkanes ?
A homologous serious with the general formula CnH2n+1
What is the general formula for haloalkanes ?
CnH2n+1
What are the prefixes for the haloalkanes ?
Fluoro
Chloro
Bromo
Iodo
What functional groups are added to the haloalkanes ?
A halogen
Fluorine
Chlorine
Bromine
Iodine
Draw 1-chloropentane
In notes
Draw 1,2-dibromopropane
How’s
Draw iodoethane
Notes
What type of bonds do alkanes have and what does this make them ?
Double bonds which means they are unsaturated.
What are structural isomers ?
Structural isomers have the same molecular formula but a different structure.
What is chain isomerism ?
Branches in different ways but same molecular formula.
What is positional isomerism ?
Same molecular formula but the functional group moves.
What is functional group isomerism.
Same molecular formula but different functional groups.
What causes isomers to differ in melting points ?
Molecules with no branching have higher melting and boiling points because their surface area and therefore more van der waals are created.
Do branched or unbranched isomers have higher melting points.
Unbranched because they have a larger surface area and therefore more van der waals forces.
What is the general formula of alcohols
CnH2n+1OH
Write the names of the first 6 alcohols.
Methanol Ethanol Propanol Butanol Pentanol Hexanol
Draw CH3CH2OHCH3 and name it
Butan-2-ol
What is an R structure
A chain of atoms
What is a primary structure.
Have one r group. 2 hydrogen’s and 1 OH
What is a secondary the secondary structure of an alcohol
2 r groups
1 H
And 1 OH
What is the tertiary structure of an alcohol
3 r groups
No hydrogen’s
1 OH
What are aldehydes and what are their general equation ?
They are known as carbonyls and have the general formula CnH2nO.
What are key tones and what are their general formula.
Collectively known as carbonyls
CnH2nO
Give examples of carbonyls and what are there general formula ?
Aldehydes
Ketones
CnH2nO
Describe the structure of an aldehyde.
One of the groups attached to the carbon is a hydrogen atom, and the other is either a hydrogen atom or an alkyl group.
How are aldehydes names ?
They all end in al
Ethanal
Methanal
Propanal
Describe the structure of ketones.
Both of the groups attached to the carbon are alkyl groups.
How are ketones named.
End in one
Ethanone
Methanone
What is the general formula of carboxylic acids ?
CnH2nO2
Draw the functional group of carboxylic acids.
In notes
How are carboxylic acids named ?
Methanoic acid
Butanoic acid
Why are most carboxylic acid chains short ?
They can form hydrogen bonds with water so have short chains to make them highly soluble.
Describe the solubility of carboxylic acids.
They form hydrogen bonds and have short chains so are highly soluble in water but are often less soluble in non-polar solvents.
Describe the chain lengths of the carboxylic acids.
Short
Draw the displayed formula of a aldehyde
In notes
What is the general formula for hexane?
C6 H14
What is crude oil
A mixture of hydrocarbons mainly composed of straight and branched alkanes.
Can have cycloaklanes and arenes which are hydrogen’s containing a ring of carbons as well as impurities such as sulfur compounds.
What are cycloalkanes and arenes ?
They are hydrogen’s containing a ring of carbons and impurities such as sulfur containing compounds.
What deciphers the exact composition of crude oil.
The place where it has been extracted from.
Why is crude oil not useful.
It is very viscous (thick and sticky) and therefore does not have many uses.
What binds are broken during fractional distillation.
Intermolecular van der waals forces.
Describe the heat gradient in a fractionating column.
The tower is cooler at the top and heavier at the bottom where the source is constantly heated to keep vaporisation constant.
In fractional distillation, what decides where each fraction leaves the tower.
Based on their boiling points.
Longer chain alkanes will have more van der waals forces so they have a higher boiling points. This means they will leave the tower at the bottom of the column where there is higher temperatures.
Whereas shorter chain alkanes will leave the tower at the top where it is cooler as less thermal energy is required to break the fewer intermolecular van der waals forces.
In general, what are lighter fractions of fractional distillation used for.
Fuels.
In general , what are heavier fractions of fractional distillation used for ?
Lubricants.
How will different isomers have different boiling points.
Branched isomers will have smaller surface area, this means there are fewer van der waals intermolecular forces and therefore branched isomers will have a lower boiling point.
What is each fraction that leaves a fractionating column ( what does it contain) ?
A mixture of hydrocarbons with similar boiling points which can be separated further into outer components.
How many carbons are in a chain of a gas hydrocarbon.
1-4
How many carbons are in a chain of hydrocarbons which is a liquid.
5-15
How many carbons are in a chain of hydrocarbons which is a solid.
More than 15
If a hydrocarbon has more than 15 carbon in its chain, what state is it likely to be ?
Solid
If a hydrocarbon has 5-15 carbons in its chain, what state is it likely to be ?
Liquid
If a hydrocarbon has less than 5 carbons in its chain , what state is it likely to be ?
Gas
Why is the demand for the fractions of fractional distillation higher than the demand for crude oil.
The short chain alkanes from fractional distillation are very economically valuable and have low boiling points.
Crude oil is not economically valuable as it has no uses.
Give some fractions and there uses.
Liquid petroleum gas - camping stoves and gas for cooking Gasoline - fuel for cars Naphtha - petrochemicals Kerosine- fuel for aircrafts Diesel - fuel for Lorries Lubricating oil- lubrication Fuel oil - fuel for ships Wax- candles
What is gasoline used for
Fuel for cars
What is liquefied petroleum gas used for.
Gas for cooking
Camping stoves
What is naphtha used for ?
Petrochemicals
What is kerosine used for ?
Fuel for aircrafts
What is diesel used for ?
Fuel for lorries
What is fuel oil used for ?
Fuel for ships.
What is cracking ?
Cracking is a process that splits long chain alkanes into shorter chain alkanes , alkanes and hydrogen.
What are the uses of cracking ?
Increases the volume of gasoline and other economically valuable fractions.
Increases cycloalkanes and branching in chains which is important for petrol.
Produced alkanes which are an important feedstock for chemicals and are also used to make plastics.
Produces aromatic hydrocarbons which are needed for petrochemicals and motor fuels.
What are aromatic hydrocarbons used for ?
Petrochemicals and motor fuels.
Why are alkanes needed widely ?
They need to be polymerised to produce plastics.
What binds does cracking break.
Mainly C-C but some C-H
Why are more C-C bonds broken than C-H.
C-H bonds are stronger and therefore require a lot of thermal energy to be broken.
What are the 2 types of cracking.
Thermal
Catalytic
What are the conditions for thermal cracking ?
450-909 degrees
7000 kilopascals
No air so combustion can’t occur
Molecules move around so vigouously that C-C bonds break.
How does thermal cracking work.
The high pressure and temperature causes the C-C bonds to gain so much kinetic energy that they break.
Why does thermal cracking have no air.
So combustion can’t occur.
How are the products varied based on the different temperatures of thermal cracking ?
Higher temperature = shorter chain products.
Why are all components fractionally distilled after cracking ?
So the products can be split up and refined into smaller fractions again.
What are the conditions for catalytic cracking ?
Relatively high temperature but lower than thermal - 450 degrees.
Slight pressure - 1-2 atmospheres.
Zeolite catalysts which is often ground to create a larger surface area
Fractionally distilled after cracking
What is the catalyst used in catalytic cracking ?
Zeolite
Compare the different type of cracking.
Thermal can use all fractions.
Catalytic cannot use all of the fractions such as the long ones.
Catalytic produces more arenes which are useful for feedstock chemicals.
Catalytic produces more branched and cyclic alkanes which are useful for fuels.
Catalytic is cheaper.
What is the definition of combustion ?
Alkanes react with oxygen in the air to give carbon dioxide and water.
Why are alkanes good fuels ?
Good fuels because when the strong carbon-carbon and carbon-hydrogen bonds are broken, a lot of energy is released.
What is complete combustion ?
Enough oxygen , therefore carbon dioxide and water are produced.
What is incomplete combustion ?
Insufficient oxygen is present therefore carbon monoxide or carbon particles and water are produced.
What are the products of incomplete combustion ?
Carbon monoxide or carbon particles and water
What is carbon monoxide and why is it dangerous.
Carbon monoxide is a poisonous gas and can cause death by asphyxiation in the red blood cells.
What are the effects of production of carbon particles during incomplete combustion ?
Solid spot produced causes asthma and lung cancer.
Write about carbon dioxide as a pollutant
E.g effects and solutions
Carbon dioxide is a non-toxic has which is naturally removed by plants.
Levels have increased since the industrial revolution due to more cars being used and manufacturing increasing.
Carbon dioxide is a greenhouse gas as it prevents the earths heat from escaping into space.
This means that the polar ice caps melt, sea levels rise, flooding , damage to eco-systems.
If we plant more trees, algae systems and encourage bike use and walking levels of carbon dioxide will decrease.
What is the greenhouse effect ?
Greenhouse gasses from carbon dioxide, water and methane absorb infrared radiation from solar radiation due to their C-O, O-H and C-H bonds.
How can we reduce carbon monoxide carbon particles production during combustion ?
Ensure complete combustion by adding O2.
What are the issues with unburnt fuel from combustion ?
Unburnt fuel causes harmful health problems.
A lot of the alkanes left are volatile and escape before being burnt.
They can cause greenhouse gases.
What are the solutions to unburnt fuel during combustion ?
Add catalytic converters in cars and keep air-right systems in petrol stations to minimise release of fuel.
How are oxides of nitrogen formed during combustion ?
Formed when nitrogen and oxygen in the air react during combustion.
What do oxides of nitrogen from combustion cause ?
Acid rain which means erosion of buildings, killing plants and trees, contamination of lakes
How can oxides of nitrogen from combustion be reduced.
Add catalytic converters in cars.
What are the pollutants caused by combustion ?
Carbon dioxide Carbon monoxide Carbon particles Unburnt fuel Oxides of nitrogen Sulphur dioxide
How do catalytic converters work ?
Catalytic convertors work by changing carbon monoxide and oxides of nitrogen into carbon dioxide , water and N2 which are all in harmful.
What are catalytic convertors made of. Be exact.
Metals :
Platinum
Palladium
Rhodium
What does a catalytic convertors change carbon monoxide into and write an equation for this.
Carbon monoxide to carbon dioxide
2CO + 2NO = 2CO2 + N2
What are oxides of nitrogen converted to by a catalytic convertor ?
N2 and carbon dioxide
What happens to unburnt hydrocarbons by a catalytic convertor ?
They are fully oxidises into carbon dioxide and water.
What is sulfur dioxide caused by (combustion topic).
Caused by fuels which contain sulphur impurities
What does the pollutant sulphur dioxide from combustion cause ?
Acid rain
Write the equation for the production of the pollutant sulphur dioxide during combustion
S(s) + O2 (g) = SO2 (g)
How can levels of sulphur dioxide production be reduced.
Ensure petrol companies remove sulphur impurities.
Flue has disulpharisarion
How does flue gas disulpharisarion Work ?
Calcium oxide or calcium carbonate is coated onto mesh to increase its surface area. This then bonds with the sulphur dioxide causing and acid base neutralisation reaction which produced the salt calcium sulphate.
Calcium sulphate is them oxidised to CaSO4 and sold to make plaster.
What two substances can be used as reactants to sulphur dioxide in flue gas disulpharisarion ?
Calcium oxide
Calcium carbonate
Write the equation for flue gas disulpharisarion
CaO + SO2 = CaSO3
CaSO3 + O2 = CaSO4
Why is propane for camping stoves often stored as a liquid not a gas.
Occupies a smaller volume.
