AQA A LEVEL ORGANIC CHEMISTRY AND PHYSICAL
COMPREHENSIVE QUESTIONS AND CORRECT GRADE A+
NEWEST 2024 UP DATE
Isomer
Molecules with the same molecular formula but have different molecular structures or a
different arrangement of atoms in space
Stereoisomerism
Two or more compounds have the same structural formula but they differ in the
arrangement of bonds in space
Optical isomerism
Occurs when four different substituents are bonded to one carbon atom resulting in two
isomers that are non-superimposable mirror images of one another
Optical isomer
Pairs of molecules that are non-superimposable mirror images
Structural Isomerism
Molecules with the same molecular formula but different structural formulas
Chain Isomerism
Structural Isomerism where molecules have the same functional group but different
branches
Positional Isomerism
Structural Isomerism where molecules have the same functional but in a different
position
Functional Group Isomerism
Structural Isomerism where molecules different functional groups
Free radical substitution
Mechanism for halogenation of alkanes
Initiation
First step of free radical substitution - 2 free radicals are produced through homolytic
bond fission
Propagation
Second step of free radical substitution
Termination
Third step of free radical substitution - 2 free radicals combine
Homolytic Bond Fission
Process during initiation reaction in free radical substitution (caused by UV light)
Fractional Distillation
The separation of different chain length hydrocarbons in crude oil by boiling point
Catalytic Cracking
Breaking large chain molecules into smaller ones using a catalyst
Zeolite (sodium aluminium silicate) with large surface area
Catalyst used for catalytic cracking
Fuels with high octane rating
Products of catalytic cracking of hydrocarbons
, Octane Rating
A measure of how much pressure fuel can withstand before igniting
Thermal Cracking
Breaking large chain molecules into smaller ones using high pressure and temperature
700-1200K, 70atm
Conditions for Thermal Cracking in Kelvin and atm
short straight chained alkanes and alkenes
Products of Thermal Cracking of hydrocarbons
Reforming
Catalytic process in which straight chained molecules are converted to branched forms
for a higher octane rating
500C, Al2O3
Conditions for Reforming
acid rain
Danger of sulfur dioxide
form nitrogen dioxide, lung damage, acid rain, photochemical smog
Danger of nitrogen oxides
asthma attacks
Danger of particulates
Fuels with lead additive
Cause of particulates
Catalytic converter
Device that converts harmful gases into less harmful ones in a car
Platinum, Palladium, Rhodium
Chemicals that are thinly spread on a honeycomb framework in a catalytic converter
Sigma bond
Bond that forms when two s orbitals or and s and a p orbital overlap
Pi bond
Bond that forms when two p orbitals overlap
Stereoisomerism
Isomerism when molecules have the same structural formula but different arrangements
in space
Geometric Isomerism
Stereoisomerism caused by restricted rotation around the double bond
Electrophile
An electron deficient atom or part of a molecule that can form covalent bond by
accepting a lone pair of electron
Carbocation
A carbon atom within a molecule with a positive charge
tertiary carbocation
What is more stable: primary or tertiary carbocation?
positive inductive effect
What causes tertiary carbocations to be more stable than primary carbocations?
Halogen in inert solvent, dark, RTP
Reagent and conditions: Alkene to Halogenalkane (two Halide groups)
Bromine Water, RTP, dark
COMPREHENSIVE QUESTIONS AND CORRECT GRADE A+
NEWEST 2024 UP DATE
Isomer
Molecules with the same molecular formula but have different molecular structures or a
different arrangement of atoms in space
Stereoisomerism
Two or more compounds have the same structural formula but they differ in the
arrangement of bonds in space
Optical isomerism
Occurs when four different substituents are bonded to one carbon atom resulting in two
isomers that are non-superimposable mirror images of one another
Optical isomer
Pairs of molecules that are non-superimposable mirror images
Structural Isomerism
Molecules with the same molecular formula but different structural formulas
Chain Isomerism
Structural Isomerism where molecules have the same functional group but different
branches
Positional Isomerism
Structural Isomerism where molecules have the same functional but in a different
position
Functional Group Isomerism
Structural Isomerism where molecules different functional groups
Free radical substitution
Mechanism for halogenation of alkanes
Initiation
First step of free radical substitution - 2 free radicals are produced through homolytic
bond fission
Propagation
Second step of free radical substitution
Termination
Third step of free radical substitution - 2 free radicals combine
Homolytic Bond Fission
Process during initiation reaction in free radical substitution (caused by UV light)
Fractional Distillation
The separation of different chain length hydrocarbons in crude oil by boiling point
Catalytic Cracking
Breaking large chain molecules into smaller ones using a catalyst
Zeolite (sodium aluminium silicate) with large surface area
Catalyst used for catalytic cracking
Fuels with high octane rating
Products of catalytic cracking of hydrocarbons
, Octane Rating
A measure of how much pressure fuel can withstand before igniting
Thermal Cracking
Breaking large chain molecules into smaller ones using high pressure and temperature
700-1200K, 70atm
Conditions for Thermal Cracking in Kelvin and atm
short straight chained alkanes and alkenes
Products of Thermal Cracking of hydrocarbons
Reforming
Catalytic process in which straight chained molecules are converted to branched forms
for a higher octane rating
500C, Al2O3
Conditions for Reforming
acid rain
Danger of sulfur dioxide
form nitrogen dioxide, lung damage, acid rain, photochemical smog
Danger of nitrogen oxides
asthma attacks
Danger of particulates
Fuels with lead additive
Cause of particulates
Catalytic converter
Device that converts harmful gases into less harmful ones in a car
Platinum, Palladium, Rhodium
Chemicals that are thinly spread on a honeycomb framework in a catalytic converter
Sigma bond
Bond that forms when two s orbitals or and s and a p orbital overlap
Pi bond
Bond that forms when two p orbitals overlap
Stereoisomerism
Isomerism when molecules have the same structural formula but different arrangements
in space
Geometric Isomerism
Stereoisomerism caused by restricted rotation around the double bond
Electrophile
An electron deficient atom or part of a molecule that can form covalent bond by
accepting a lone pair of electron
Carbocation
A carbon atom within a molecule with a positive charge
tertiary carbocation
What is more stable: primary or tertiary carbocation?
positive inductive effect
What causes tertiary carbocations to be more stable than primary carbocations?
Halogen in inert solvent, dark, RTP
Reagent and conditions: Alkene to Halogenalkane (two Halide groups)
Bromine Water, RTP, dark
