AQA AS Organic Chemistry Exam |
Questions And Answers | Newest
Exam 2026-2027 |
Define the term 'Homologous series' -ANSWER A family of organic compounds that have
the same general formula and similar chemical properties
Define the term 'Structural isomer' -ANSWER A molecule with the same molecular
formula as, but different structural formula to another molecule
Define the term 'Stereoisomerism' -ANSWER A molecule which has the same structural
formula as another molecule, but has its atoms arranged differently in space
Define the term 'E-isomer' -ANSWER A stereoisomer of an alkene that had the two
highest priority groups on opposite sides of the carbon-carbon double bond
Define the term 'Z-isomer' -ANSWER A stereoisomer of an alkene that has the two
highest priority groups on the same side of the carbon-carbon double bond
(To help you remember it: Zee Zame Zide).
Define the term 'E/Z isomerism' -ANSWER A type of stereoisomerism that is cause ld by
the restricted rotation about a carbon-carbon double bond, each of he carbon atoms
must have two different groups attached
Define the term 'Alkanes' -ANSWER A saturated hydrocarbon with the general formula
CnH2n+2
Define the term 'Petroleum' -ANSWER A mixture consisting mainly of alkane
hydrocarbons that can be separated into different fractions
Define the term 'Cracking' -ANSWER Long chain hydrocarbons are broken down into
shorter chain hydrocarbons. This produces a mixture of alkanes and alkenes
Describe thermal cracking. Include conditions in your ANSWER. -ANSWER Temperatures
between 700k and 1200k
Pressure of up to 7000 KPa.
1) Carbon-carbon breaks to produce two free radicals.
2) Free radicals are highly reactive and react to produce many alkenes and some
alkanes.
,Why are long chain hydrocarbons not kept under high temperatures for long amounts of
time? -ANSWER At higher temperatures, these chains decompose. Given enough time,
this will eventually result in products which are only hydrogen gas and solid carbon.
Describe catalytic cracking. Include conditions in your ANSWER. -ANSWER Zeolite
catalyst.
720K.
Low pressure.
Hydrocarbons are mixed with a catalyst which has been ground into a fine powder.
Produces lots of branched alkanes and aromatic hydrocarbons
Describe a zeolite catalyst -ANSWER A substance which has a honeycomb structure with
an enormous surface area. They are usually acidic.
What type of products are usually formed from catalytic cracking? -ANSWER Branched
alkanes
Cycloalkanes (rings)
Aromatic compounds (e.g. benzene)
Define the term 'Halogenoalkanes' -ANSWER An alkane with at least one halogen atom
in place of a hydrogen atom
Define the term 'Ozone layer' -ANSWER A layer of ozone (O3) found in the earth's upper
atmosphere which protects the earth from ultra violet radiation
Define the term 'Alkenes' -ANSWER An unsaturated hydrocarbon with the general
formula CnH2n, containing at least one carbon-carbon double bond
How can we test for the presence of a C=C double bond? -ANSWER Add bromine water
(an orange solution) to the unknown solution. If a C=C double bond is present then the
solution will decolourise (turn colourless).
What conditions are needed for an alcohol to be made from an alkene? -ANSWER Steam
High temperature
High pressure
Acid catalyst
How many sigma bonds and pi bonds are in a single bond? -ANSWER 1 sigma
0 pi
How many sigma and pi bonds are in a double bond? -ANSWER 1 sigma
1 pi
, How many sigma and pi bonds in a triple bond? -ANSWER 1 sigma
2 pi
Why can double bonds not rotate? -ANSWER Two p-orbitals have overlapped to make a
pi orbital.
Why are alkenes more chemically reactive than alkanes? -ANSWER The double bond is
electron rich.
Why are the physical properties of alkenes similar to those of the alkanes? -ANSWER
Van der Waals forces are the only type of intermolecular forces that act between both
alkanes and alkenes.
Why can single bonds rotate? -ANSWER Two p-orbitals have not overlapped. There are
no pi orbitals.
Define the term 'Bonding in alkenes' -ANSWER Involves double covalent bonds, a centre
of high electron density
Define the term 'Addition polymers' -ANSWER A long chain molecule formed by an
addition reaction. They are formed from monomers which have a carbon-carbon double
bond.
Define the term 'monomer'. -ANSWER An individual molecule that is repeated n times to
make a polymer.
Define the term 'polymer backbone' -ANSWER The longest series of covalently bonded
atoms that together create the continuous chain of the molecule
Define the term 'repeating unit' -ANSWER The smallest group of atoms that produce the
polymer when repeated over and over
State one use for poly(ethene) or polythene -ANSWER Carrier bags or washing up bowls
State one use for poly(propene) or polypropylene -ANSWER Yoghurt containers or car
bumpers
State one use for poly(chloroethene) or poly(vinyl chloride) -ANSWER Aprons or
drainpipes
State one use for poly(propenenitrile) or acrylic -ANSWER Clothing fabrics
State one use for poly(phenylethene) or polystyrene -ANSWER Packing materials or
electrical insulation
Questions And Answers | Newest
Exam 2026-2027 |
Define the term 'Homologous series' -ANSWER A family of organic compounds that have
the same general formula and similar chemical properties
Define the term 'Structural isomer' -ANSWER A molecule with the same molecular
formula as, but different structural formula to another molecule
Define the term 'Stereoisomerism' -ANSWER A molecule which has the same structural
formula as another molecule, but has its atoms arranged differently in space
Define the term 'E-isomer' -ANSWER A stereoisomer of an alkene that had the two
highest priority groups on opposite sides of the carbon-carbon double bond
Define the term 'Z-isomer' -ANSWER A stereoisomer of an alkene that has the two
highest priority groups on the same side of the carbon-carbon double bond
(To help you remember it: Zee Zame Zide).
Define the term 'E/Z isomerism' -ANSWER A type of stereoisomerism that is cause ld by
the restricted rotation about a carbon-carbon double bond, each of he carbon atoms
must have two different groups attached
Define the term 'Alkanes' -ANSWER A saturated hydrocarbon with the general formula
CnH2n+2
Define the term 'Petroleum' -ANSWER A mixture consisting mainly of alkane
hydrocarbons that can be separated into different fractions
Define the term 'Cracking' -ANSWER Long chain hydrocarbons are broken down into
shorter chain hydrocarbons. This produces a mixture of alkanes and alkenes
Describe thermal cracking. Include conditions in your ANSWER. -ANSWER Temperatures
between 700k and 1200k
Pressure of up to 7000 KPa.
1) Carbon-carbon breaks to produce two free radicals.
2) Free radicals are highly reactive and react to produce many alkenes and some
alkanes.
,Why are long chain hydrocarbons not kept under high temperatures for long amounts of
time? -ANSWER At higher temperatures, these chains decompose. Given enough time,
this will eventually result in products which are only hydrogen gas and solid carbon.
Describe catalytic cracking. Include conditions in your ANSWER. -ANSWER Zeolite
catalyst.
720K.
Low pressure.
Hydrocarbons are mixed with a catalyst which has been ground into a fine powder.
Produces lots of branched alkanes and aromatic hydrocarbons
Describe a zeolite catalyst -ANSWER A substance which has a honeycomb structure with
an enormous surface area. They are usually acidic.
What type of products are usually formed from catalytic cracking? -ANSWER Branched
alkanes
Cycloalkanes (rings)
Aromatic compounds (e.g. benzene)
Define the term 'Halogenoalkanes' -ANSWER An alkane with at least one halogen atom
in place of a hydrogen atom
Define the term 'Ozone layer' -ANSWER A layer of ozone (O3) found in the earth's upper
atmosphere which protects the earth from ultra violet radiation
Define the term 'Alkenes' -ANSWER An unsaturated hydrocarbon with the general
formula CnH2n, containing at least one carbon-carbon double bond
How can we test for the presence of a C=C double bond? -ANSWER Add bromine water
(an orange solution) to the unknown solution. If a C=C double bond is present then the
solution will decolourise (turn colourless).
What conditions are needed for an alcohol to be made from an alkene? -ANSWER Steam
High temperature
High pressure
Acid catalyst
How many sigma bonds and pi bonds are in a single bond? -ANSWER 1 sigma
0 pi
How many sigma and pi bonds are in a double bond? -ANSWER 1 sigma
1 pi
, How many sigma and pi bonds in a triple bond? -ANSWER 1 sigma
2 pi
Why can double bonds not rotate? -ANSWER Two p-orbitals have overlapped to make a
pi orbital.
Why are alkenes more chemically reactive than alkanes? -ANSWER The double bond is
electron rich.
Why are the physical properties of alkenes similar to those of the alkanes? -ANSWER
Van der Waals forces are the only type of intermolecular forces that act between both
alkanes and alkenes.
Why can single bonds rotate? -ANSWER Two p-orbitals have not overlapped. There are
no pi orbitals.
Define the term 'Bonding in alkenes' -ANSWER Involves double covalent bonds, a centre
of high electron density
Define the term 'Addition polymers' -ANSWER A long chain molecule formed by an
addition reaction. They are formed from monomers which have a carbon-carbon double
bond.
Define the term 'monomer'. -ANSWER An individual molecule that is repeated n times to
make a polymer.
Define the term 'polymer backbone' -ANSWER The longest series of covalently bonded
atoms that together create the continuous chain of the molecule
Define the term 'repeating unit' -ANSWER The smallest group of atoms that produce the
polymer when repeated over and over
State one use for poly(ethene) or polythene -ANSWER Carrier bags or washing up bowls
State one use for poly(propene) or polypropylene -ANSWER Yoghurt containers or car
bumpers
State one use for poly(chloroethene) or poly(vinyl chloride) -ANSWER Aprons or
drainpipes
State one use for poly(propenenitrile) or acrylic -ANSWER Clothing fabrics
State one use for poly(phenylethene) or polystyrene -ANSWER Packing materials or
electrical insulation
