Switching to AQA from OCR Chemistry B
If you're thinking of switching to AQA from OCR GCSE in Chemistry B (Gateway
Science - J264) for teaching from September 2016, this resource will provide a
helpful comparison of the subject content and assessment for each awarding
body. It directly compares the OCR Chemistry B specification, with the new
specification (8462) for 2016 onwards.
Comparison overview
Although both specifications are organised by concept, these concepts have been
grouped into different topics. This means that the content in the AQA
specification can be found in several OCR topics. AQA and OCR also give different
emphasis to specific topics.
There is flexibility to co-teach the AQA Chemistry and Combined Science: Trilogy
(8464) courses.
Assessment
New AQA specification Current OCR specification
Two externally assessed written
papers (1 hour 45 minutes).
Paper 1 assesses sections 1 to 5
of the subject content.
Paper 2 assesses sections 6 to 10,
but may also include the
fundamental principles in sections
1 to 3.
Eight required practicals should
be carried out by students and
may be examined in the written
papers to assess practical skills.
Three exam papers overall.
Two externally assessed written
papers:
One paper of 1 hour 15
minutes. Covering content in
modules C1, C2 and C3 (35%
of qualification).
One paper of 1 hour 30
minutes. Covering content in
modules C4, C5 and C6.
Includes 10 mark data
response question (40% of
qualification).
One controlled assessment exam
paper (25% of qualification).
Content
Practicals
New AQA specification Current OCR specification
The required practicals are clearly
listed, as are opportunities for
development of skills identified in
the right-hand column of the
specification. These should
encourage more practical work,
which will motivate students and
encourage the transfer of skills
across the subject.
Opportunities for practical work are
flagged in the introduction to each
module.
Working scientifically
New AQA specification Current OCR specification
Specification reference: WS 1.1 to
WS 4.6
Specification reference: Ideas about
science
'Working scientifically' encompasses
all the activities that scientists do. It
is woven throughout the
specification and written papers.
There are cross-references to
relevant skills development
opportunities in the subject
content.
N/A
Atomic structure and the periodic table
4.1.1 A simple model of the atom, symbols, relative atomic mass, electronic
charge and isotopes
New AQA specification Current OCR specification
Specification reference:
4.1.1.1 Atoms, elements and
compounds
Specification reference:
C4: Fundamental Concepts
Both specifications require recognition and manipulation of chemical
symbols and formulae to describe molecular composition and reactions
using an understanding of atoms and molecules, elements and
compounds.
New AQA specification Current OCR specification
Equations and balancing can be found at Foundation Tier in both
specifications.
The OCR specification refers to recollection of particular compounds'
formulae in an introductory item for each topic entitled 'Fundamental
Chemical Concepts'.
Recognition of symbols of the first
20 elements.
N/A
Specification reference:
4.1.1.2 Mixtures
Specification reference:
Fundamental Concepts: C4
There is no equivalent summary topic in the OCR specification, although all
of the separation techniques are covered throughout the specification.
Definition of a mixture. N/A
Specification reference: 4.1.1.3
Scientific models of the atom
Specification reference: C4a
Both specifications refer to developmental stages in the model of atomic
structure as an example of the development of a scientific theory.
N/A Reference to Dalton and Tomson.
Specification reference:
4.1.1.4 Relative electrical charges of
subatomic particles
Specification reference:
Atomic Structure: C4a (also refers
to masses of subatomic particles).
Specification reference:
4.1.1.5 Size and mass of atoms
Specification reference:
Fundamental concepts: C4 and C4a
Both specifications give the relative masses of the fundamental particles.
Calculation of the number of protons, neutrons and electrons in a charged
particle is Higher Tier only in the OCR specification, but for students of all
abilities in the AQA specification.
Specification reference:
4.1.1.6 Electronic structure
Specification reference: C4a
The content of both specifications is the same.
4.1 2 The periodic table
New AQA specification Current OCR specification
Specification reference:
4.1.2.1 The periodic table
Specification reference:
C4a
C4c
C4d
The content is similar, although patterns and their explanation are
separated into description of respective groups in the OCR specification.
Prediction of possible reactivity
from the position in the periodic
table.
N/A
Specification reference:
4.1.2.2. The development of the
periodic table
Specification reference: C4c
Both specifications consider the contribution of Mendeleev and earlier
contributors. OCR specification includes the ideas of Döbereiner and
Newlands.
OCR Higher Tier: confirmation of Mendeleev's structure through discovery
of unknown elements and investigation into atomic structure.
Knowledge of isotopes, explaining
why the order based on atomic
weights is not always correct.
N/A
Specification reference:
4.1.2.3 Metals and non-metals
Specification reference:
C2c
C4b to g
There is no equivalent summary topic in the OCR specification, however:
Explanation of the formation of positive and negative ions by metals
and non-metals is included in the sections on bonding (C4b, C4c).
Description of locations in the periodic table is referred to in topics
on respective groups (C4d, C4e, C4f).
Consideration of metallic properties is in the topic on metals and
alloys (C2c, C4g).
OCR doesn’t cover differences in properties.
Specification reference:
4.1.2.4 Group 0
N/A
New AQA specification Current OCR specification
Specification reference:
4.1.2.5 Group 1
Specification reference: C4d
The content is very similar in both specifications:
reactions of the alkali metals with water
trends in reactivity moving down the group.
Comparison of Group 1 metals'
density with water.
Reference to reactions and
associated products of Group 1
metals with non-metals.
Construction of balanced symbol
equations for reactions with water
(both Foundation and Higher Tier).
Flame tests (identical content is
covered in section 4.8.3 of the AQA
specification).
Specification reference:
4.1.2.6 Group 7
Specification reference: C4e
The content is very similar. Both specifications include reactions with
metals (alkali metals in the OCR specification) and displacement reactions
leading to the pattern in reactivity down the group.
OCR Higher Tier: recall the formulae of bromides and iodides.
AQA specification requires students of all abilities to know the formulae of
the halide ions.
The ionic or molecular nature of the
products formed with metals and
non-metals.
Recall of some uses of Group 7
elements.
Colours and physical states of the
halogens at room temperature.
4.1 3 Properties of transition elements
New AQA specification Current OCR specification
Specification reference:
4.1.3.1 Comparison with Group 1
elements
Specification reference: C4f
Specification reference:
4.1.3.2 Typical properties
Specification reference: C4f
The OCR specification has more detail, it includes identification based on
position in the periodic table and physical properties with specific
New AQA specification Current OCR specification
examples of colour and examples of uses as catalysts.
N/A Description of thermal
decomposition reactions of
transition metal carbonates with
word equations (Foundation Tier).
Higher Tier: balanced symbol
equations.
Bonding, structure and the properties of matter
4.2.1 Chemical bonds, ionic, covalent and metallic
New AQA specification Current OCR specification
Specification reference:
4.2.1.1 Chemical bonds
Specification reference:
C4b to c
C4g
There is no equivalent summary-section in the OCR specification.
However, OCR covers all the points in topics for each type of bonding.
Specification reference:
4.2.1.2 Ionic bonding
Specification reference: C4b
The content is very similar in both specifications: formation and transfer
of ions to form compounds.
Dot and cross diagrams to represent ionic bonding are required by
students of all abilities in the AQA specification while this is Higher Tier
only in the OCR specification.
AQA specification requires working
out the charge on ions from Groups
1, 2, 6 and 7.
OCR requires deducting the
formula for an ionic compound
from the formula of the positive
and negative ions.
Specification reference:
4.2.1.3 Ionic compounds
Specification reference: C4b
Both specifications include a description of giant ionic structures.
Recognition of a giant ionic
structure from a diagram or model.
Deduction of the empirical formula
from the model and a description of
Knowledge of sodium chloride and
magnesium oxide structures,
comparison of their physical
properties.
New AQA specification Current OCR specification
its limitations in representing a
giant structure.
Reference to sodium chloride.
Higher Tier: explanation of
differences in these properties
(structure, bonding and prediction
of the properties of other
substances with similar structure).
Specification reference:
4.2.1.4 Covalent bonding
Specification reference:
C4c and C3h
Description of covalent bonding: shared electrons with reference made
to small molecules, polymers and giant covalent structures.
Dot and cross diagrams are
required for 8 specific molecules at
both Higher and Foundation Tiers.
Deduction of molecular formula
from a given model or diagram and
a description of the model's
limitations.
Carbon dioxide and water as small
covalent molecules; description of
their physical properties.
Higher Tier:
explanation of these
properties in terms of
structure and bonding
dot and cross diagrams.
Specification reference:
4.2.1.5 Metallic bonding
Specification reference:
C5.4.25
The content is similar, but is Higher Tier only in the OCR specification,
unlike in the AQA specification.
4.2.2 How bonding and structure are related to the properties of substances
New AQA specification Current OCR specification
Specification reference:
4.2.2.1 The three states of matter
This topic is not covered in the
OCR specification although an
understanding of most of the
ideas is assumed, eg in C1g,
Smells, and C1h, Paints and
Pigments.
Specification reference:
4.2.2.2 State symbols
Specification reference: C5h
New AQA specification Current OCR specification
The content is the same, but in the OCR specification recall of state
symbols is for students of all abilities and writing balanced equations,
including state symbols, is Higher Tier only. Both are for students of all
abilities in the AQA specification.
Specification reference:
4.2.2.3 Properties of ionic
compounds
Specification reference: C4b
Description of the structure of ionic compounds is similar in both
specifications.
Knowledge of sodium chloride only. Knowledge of both sodium
chloride and magnesium oxide.
Specification reference:
4.2.2.4 Properties of small
molecules
Specification reference:
C1a, C1e and C4c
The content of both specifications is almost the same.
The knowledge that intermolecular forces increase with size of
molecules and the effect on boiling point is included in the OCR
specification in the hydrocarbons context.
Specification reference:
4.2.2.5 Polymers
Specification reference:
C1d, C1e and C4b
The content of both specifications is very similar: awareness of a
polymer's structure and the effect of intermolecular forces on melting
point.
N/A The effect of intermolecular forces
on strength, stiffness and
hardness of a polymer.
Specification reference:
4.2.2.6 Giant covalent structures
Specification reference: C3h
Understanding of giant covalent structure is similar in both
specifications.
The OCR topic is covered in the context of allotropes of carbon.
Explanation of structure and bonding properties is required at Higher
Tier only.
Examples of diamond, graphite and
silica.
Examples of diamond and
graphite only.
New AQA specification Current OCR specification
Specification reference:
4.2.2.7 Properties of metals and
alloys
Specification reference:
C2c and C4g
The description of metal structures and properties is similar in both
specifications.
A detailed explanation for the
difference in properties between an
alloy and its compositional metals.
Recollection of the main metals in
amalgam, brass and solder with
examples of use.
Limited to recognition of the
differences only.
Higher Tier: detailed description
of metallic bonding and its effect
on properties.
Specification reference:
4.2.2.8 Metals as conductors
Specification reference: C4g
Both specifications cover electrical conductivity.
OCR Higher Tier: explanation of electrical conductivity.
Thermal and electrical conductivity. N/A
4.2.3 Structure and bonding of carbon
New AQA specification Current OCR specification
Specification reference:
4.2.3.1 Diamond
Specification reference: C3h
The content is almost identical in both specifications.
OCR specification also includes solubility as a property.
Specification reference:
4.2.3.2 Graphite
Specification reference: C3h
The content is similar in both specifications.
AQA specification describes the bonding of graphite in detail.
Specification reference:
4.2.3.3 Graphene and fullerenes
Specification reference: C3h
New AQA specification Current OCR specification
Detailed explanation of the
structure of graphene, fullerenes
and carbon nanotubes.
OCR specification doesn’t refer to
graphene.
Detailed structure of fullerenes is
not required, although an
explanation of the structure of
nanotubes is required at Higher
Tier.
4.2.4 Bulk and surface properties of matter including nanoparticles
New AQA specification Current OCR specification
Specification reference:
4.2.4.1 Sizes of particles and their
properties
Specification reference: C3h
Both specifications consider the relative size of nanoparticles and the
effect on their properties.
A mathematical consideration of
surface area to volume ratio.
N/A
Specification reference:
4.2.4.2 Uses of nanoparticles
Specification reference: C3h
The applications of nanoparticles are different in the two specifications.
Quantitative chemistry
4.3.1 Conservation of mass and the quantitative interpretation of chemical
equations
New AQA specification Current OCR specification
Specification reference:
4.3.1.1 Conservation of mass and
balanced chemical equations
Specification reference:
C1 to 6 Fundamental
Chemical Concepts
C3d
C5a
The OCR specification covers balanced chemical equations as a
fundamental concept respective to each section of the specification.
Detailed conservation of mass and how this quantitatively relates to
New AQA specification Current OCR specification
balanced equations is found in section C3d and C5a.
Specification reference:
4.3.1.2 Relative formula mass
Specification reference:
C1 to 6 - Fundamental
Chemical Concepts
C3d
C5a
In the OCR specification construction of balanced chemical equations is
referred to as a fundamental concept prior to each respective section.
The use of formula mass to construct equations and perform
quantitative calculations is found in section C3d and C5a.
Specification reference:
4.3.1.3 Mass changes when a
reactant or product is a gas
N/A
4.3 2 Uses of amount of substance in relation to masses of pure substances
New AQA specification Current OCR specification
Specification reference:
4.3.2.1 Moles (Higher Tier only)
Specification reference:
C5a and C5b
This content is similar in both specifications.
Avogadro constant. N/A
Specification reference:
4.3.2.2 Amounts of substances in
equations
Specification reference:
C5a and C5b
Both specifications require the calculation of masses and products from
balanced equations (Higher Tier only).
Mathematical skills: substitution,
rearranging equations, standard
form and mathematical symbols.
N/A
Specification reference:
4.3.2.3 Using moles to balance
equations (Higher Tier only)
This topic is not covered in the
OCR specification. Although
similar knowledge and skills are
used in C5a and C5b.
New AQA specification Current OCR specification
Specification reference:
4.3.2.4 Limiting reactants (Higher
Tier only)
Specification reference: C3a
This concept is addressed in the
context of reaction rates.
Specification reference:
4.3.2.5 Concentration of solutions
Specification reference: C5c
The procedure for making up a
standard solution for students of
all abilities.
Both specifications consider concentration in g/dm3 and require
calculations involving mass, concentration and volume of solution
(Higher Tier only).
4.3.3 Yield and atom economy of chemical reactions
New AQA specification Current OCR specification
Specification reference:
4.3.3.1 Percentage yield
Specification reference:
C2e
C3e
C6d
Both specifications require the calculation of percentage yield given
actual and theoretical yield for students of all abilities. They also require
calculating the theoretical amount of a product form a balanced
equation (Higher Tier only in the OCR specification).
Reasons for the actual yield being
less than the theoretical yield.
The concept is referred to in
evaluation of different processes
in C2e and C6d.
Specification reference:
4.3.3.2 Atom economy
Specification reference: C3e
Content is similar in both specifications. Calculation of atom economy is
for students of all abilities.
In the OCR specification explanation of industrial ramifications is Higher
Tier only.
4.3.4 Using concentrations of solutions in mol/dm3
New AQA specification Current OCR specification
Specification reference:
4.3.4 Using concentrations of
solutions in mol/dm3
Specification reference:
C5c
C5d
Concentrations, titrations and titration calculations are addressed
similarly in both specifications.
4.3.5 Use of amount of substance in relation to volumes of gases
New AQA specification Current OCR specification
Specification reference:
4.3.5 Use of amount of substance in
relation to volumes of gases
Specification reference: C5e
This content is similar in both specifications.
However, the OCR specification focuses on measurement of gases and
limiting reactants for students of all abilities.
Higher Tier: calculations involving amounts and volumes of gas (both
specifications).
Chemical changes
4.4.1 Reactivity of metals
New AQA specification Current OCR specification
Specification reference:
4.4.1.1 Metal oxides
Specification reference:
C2d
C4d
C6c
Oxidation and reduction are defined in terms of gain and loss of oxygen
in both specifications. The OCR specification focuses on rusting. There is
reference to the oxidation of metals in C2d and C4d.
Specification reference:
4.4.1.2 The reactivity series
Specification reference:
C6c
C4d
New AQA specification Current OCR specification
The AQA specification covers reactivity in detail; it refers to an element's
tendency to form positive ions denoting its position in the reactivity
series.
OCR specification covers the reactivity of Group 1 metals in section C4d.
A series of 8 metals with a
prediction of their displacement
reactions.
The OCR specification refers to a
series of 4 metals with a
prediction of their displacement
reactions.
Specification reference:
4.4.1.3 Extraction of metals and
reduction
Specification reference:
C2c
C6c
Both specifications cover extraction of metals by carbon reduction. They
also require evaluation of specific metal extraction processes.
Unreactive metals such as gold. Focus on copper extraction.
Specification reference:
4.4.1.4 Oxidation and reduction in
terms of electrons
Specification reference:
C2c
C6c
Higher Tier content including ionic equations (both specifications).
4.4.2 Reactions of acids
New AQA specification Current OCR specification
Specification reference:
4.4.2.1 Reactions of acids with
metals
No equivalent in the OCR
specification.
However, metal/acid redox
reactions are used in sections
C3a, C3b and C3c in studying rate
of reaction. Metal displacement
reactions are referred to in
section C6c.
Specification reference:
4.4.2.2 Neutralisation of acids and
salt production
Specification reference: C2f
New AQA specification Current OCR specification
The content is very similar in both specifications:
definition of alkalis (however, only AQA defines a base)
production of salts from acids with metal oxides, hydroxides or
carbonates
deduction of the name and formula of the salt formed (deduction
of a formula is at Higher Tier only in OCR).
Specification reference:
4.4.2.3 Soluble salts
Specification reference:
C4h
C5h
Both specifications cover production, purification and drying of a soluble
salt.
The process is limited to the use of
an insoluble starting material.
There is a required practical to
make a salt from an insoluble oxide
or carbonate.
Preparation of an insoluble salt is
a suggested activity in section
C4h. Students are required to
recall stages in the preparation of
a dry sample in section C5h.
Specification reference:
4.4.2 4 The pH scale and
neutralisation
Specification reference:
C2f
C5d
The content is similar in both specifications:
ionic equation for neutralisation
litmus paper, universal indicator and pH probes
acid-alkali titrations, although there are some differences in the
treatment of these.
Ionic equations for neutralisation
reactions are required by students
of all abilities (Higher Tier only in
the OCR specification).
A required practical for students of
all abilities.
Higher Tier: calculate the
concentration of one of the
solutions, either in g/dm3 or
mol/dm3.
Higher Tier: perform calculations
involving concentration, mass,
volume and balanced equations,
although students of all abilities
may be given a formula in which
to substitute results.
All students are expected to recall
how to make up a standard
solution and to estimate the
uncertainty in the results.
New AQA specification Current OCR specification
Specification reference:
4.4.2.5 Strong and weak acids
Specification reference: C5g
Both specifications give examples of acids, although the lists are not the
same. Both describe strong and weak acids in terms of pH.
The entire topic is at Higher Tier only in the AQA specification.
Description of extent of ionisation
and the mathematical link between
pH and hydrogen ion concentration.
N/A
4.4.3 Electrolysis
New AQA specification Current OCR specification
Specification reference:
4.4.3.1 The process of electrolysis
Specification reference: C6a
The content of both specifications is very similar.
Throughout the electrolysis topic,
Higher Tier students are expected
to write and balance half-equations
for reactions at the electrodes.
N/A
Specification reference:
4.4.3.2 Electrolysis of molten ionic
compounds
Specification reference: C6a
Common content in both specifications:
lead bromide as an example
production of metals at the negative electrode and non-metals at
the positive electrode
half equations are required at Higher Tier.
The terms anode and cathode. N/A
Specification reference:
4.4.3.3 Using electrolysis to extract
metals
Specification reference: C2c
The AQA example: aluminium.
The OCR example: extraction of copper.
New AQA specification Current OCR specification
N/A Higher Tier: gain or loss of
electrons at the electrodes.
Specification reference:
4.4.3.4 Electrolysis of aqueous
solutions
Specification reference: C6a
Content is similar in both specifications. OCR focuses on brine and
sulphuric acid.
There is a required practical
investigating the electrolysis of
aqueous solutions using inert
electrodes.
Students of all abilities:
knowledge of the products at both
electrodes.
Higher Tier: half equations (both
tiers in AQA).
Specification reference:
4.4.3.5 Representation of reactions
at electrodes as half equations
N/A
Energy changes
4.5.1 Exothermic and endothermic reactions
New AQA specification Current OCR specification
Specification reference:
4.5.1.1 Energy transfer during
exothermic and endothermic
reactions
Specification reference: C3f
Both specifications require an understanding of the terms exothermic
and endothermic. AQA specification is more detailed.
Examples of exothermic and
endothermic changes.
The link between energy change
and temperature change.
Everyday uses of exothermic and
endothermic reactions.
There is a required practical
investigating the factors affecting
temperature changes in a list of
N/A
New AQA specification Current OCR specification
possible reaction mixtures.
Specification reference: 4.5.1.2
Reaction profiles
Specification reference: C6b
The OCR specification refers to energy level diagrams rather than energy
profiles. Both include activation energy. This is Higher Tier only in the
OCR specification.
Specification reference:
4.5.1.3 The energy change of
reactions
Specification reference: C3f
Content common in both specifications:
energy needed to break bonds and energy released on forming
bonds (for students of all abilities in OCR, Higher Tier in AQA)
calculation of the overall energy change from bond energy data
(Higher Tier only).
4.5.2 Chemical cells and fuel cells
New AQA specification Current OCR specification
Specification reference:
4.5.2.1 Cells and batteries
N/A
Specification reference:
4.5.2.2 Fuel cells
Specification reference: C6b
The content is very similar in both specifications:
overall reaction (Higher and Foundation Tier)
half equations (Higher Tier only).
The rate and extent of chemical change
4.6.1 Rate of reaction
New AQA specification Current OCR specification
Specification reference:
4.6.6.1 Calculating rates of
reactions
Specification reference: C3a
The OCR specification requires students to explain meaning of a
New AQA specification Current OCR specification
chemical reaction rate, including the use of appropriate units and
interpretation of data.
The AQA specification is more detailed and requires further calculation.
Rate of reaction is defined
mathematically for students of all
abilities, using units of g/s or
cm3/s.
Higher Tier: using units involving
moles.
All students are required to draw
and interpret graphs, including
drawing tangents to the curve and
using the slope as a measure of
rate.
Higher Tier: calculating the
gradient of a tangent to the curve.
N/A
Specification reference:
4.6.1.2 Factors which affect the
rates of chemical reactions
Specification reference: C3b
Both specifications include the effect of size of solid particles,
concentration of solutions, temperature and the presence of a catalyst.
Both require knowledge of how rate can be followed by collecting a gas,
weighing the mixture and formation of a precipitate or colour.
The effect of gas pressure.
Students are required to explain
the effect of size of pieces of solid
in terms of surface area to volume
ratio.
There is a required practical
investigating how concentration
changes affect the rate of a
reaction.
Students are required to interpret
information about the control of
rates of reaction in chemical
synthesis.
Specification reference:
4.6.1.3 Collision theory and
activation energy
Specification reference:
C3b
C3c
Both specifications use collision frequency to explain how rate depends
on the concentration of a solution, but there are significant differences
in the rest of the topic.
New AQA specification Current OCR specification
Surface area to volume ratio is
required to explain the effect of
changing the size of pieces of a
solid.
Energy of collisions and activation
energy is required to explain the
effect of temperature changes.
The effect of pressure changes is
also explained by collision
frequency.
The effect of changing the size of
pieces of a solid is explained in
terms of collision frequency.
The effect of temperature changes
is not covered.
Specification reference:
4.6.1.4 Factors that increase the
rate of reaction
Specification reference:
C3b
C3c
Both specifications cover the effect of changing the concentration of a
solution and the size of pieces of solid in terms of collision frequency.
The effect of pressure and
temperature changes. The effect
of temperature changes on the
energy of collision.
Students are expected to predict
and explain the effect of changing
conditions and to use simple ideas
about proportionality when using
collision theory.
N/A
Specification reference:
4.6.1.5 Catalysts
Specification reference: C3c
Both specifications define a catalyst. AQA specification explains it
provides an alternative route of lower activation energy.
Reaction profiles. N/A
4.6.2 Reversible reactions and dynamic equilibrium
New AQA specification Current OCR specification
Specification reference:
4.6.2.1 Reversible reactions
Specification reference: C2e
New AQA specification Current OCR specification
The content is similar in both specifications. However, in the ammonium
chloride dissociation example the AQA specification refers to changing
the conditions to change the direction.
Specification reference:
4.6.2.2 Energy changes and
reversible reactions
This topic is not covered in the OCR
specification. However, it may be
implicit in the effect of temperature
change on equilibrium (C5f).
Specification reference:
4.6.2.3 Equilibrium
Specification reference: C5f
Both specifications refer to a reversible reaction reaching equilibrium.
OCR Higher Tier: dynamic equilibrium, the contact process and
explanation of its conditions.
Specification reference:
4.6.2.4 The effect of changing
conditions on equilibrium (Higher
Tier only)
Specification reference: C2f
Le Chatelier's principle. N/A
Specification reference:
4.6.2.5 The effect of changing
concentration (Higher Tier only)
Specification reference: C2f
Specification reference:
4.6.2.6 The effect of temperature
changes on equilibrium
Specification reference: C2f
Full explanation of this topic is at Higher Tier only for both specifications.
The AQA specification goes into more detail, students are required to
predict the effect of a change in temperature on given reactions at
equilibrium, in terms of their endothermic/exothermic character.
Specification reference:
4.6.2.7 The effect of pressure
changes on equilibrium
Specification reference: C2f
The OCR specification requires description by students of all abilities and
explanation at Higher Tier.
Higher Tier only in the AQA specification. Students are required to
predict the effect of a change in pressure on given reactions at
equilibrium, in terms of the number of molecules on each side of the
New AQA specification Current OCR specification
balanced equation.
Organic chemistry
4.7.1 Carbon compounds as fuels and feedstock
New AQA specification Current OCR specification
Specification reference:
4.7.1.1 Crude oil, hydrocarbons
and alkanes
Specification reference:
C1a
C1d
The content is very similar in both specifications.
The origin of crude oil; the general
formula for alkanes.
N/A
Specification reference:
4.7.1.2 Fractional distillation and
petrochemicals
Specification reference: C1a
The content is very similar in both specifications. AQA emphasises the
ability of carbon atoms to form families of similar compounds with the
consequential vast array of natural and synthetic compounds.
N/A Higher Tier: detailed explanation for
fractions' different boiling points.
Specification reference:
4.7.1.3 Properties of
hydrocarbons
Specification reference:
C1a
C1b
Both specifications include the effect of molecule size on boiling point.
They also cover the complete combustion of hydrocarbons as oxidation.
The trends of viscosity and
flammability with molecular size,
their influence on the use of
hydrocarbons as fuels.
Students of all abilities are
expected to write balanced
equations for combustion
reactions.
N/A
Specification reference: Specification reference:
New AQA specification Current OCR specification
4.7.1.4 Cracking and alkenes C1a
C1d
The content is very similar, but OCR splits it across two sections.
Students of all abilities are
required to balance chemical
equations that represent cracking
using formulae of reactants and
products.
N/A
4.7.2 Reactions of alkenes and alcohols
New AQA specification Current OCR specification
Specification reference:
4.7.2.1 Structure and formulae of
alkenes
Specification reference: C1d
Nearly all of the content is specific to AQA specification.
The C=C functional group, the
general formula, the structures of
the first four alkenes.
N/A
Specification reference:
4.7.2.2 Reactions of alkenes
Specification reference:
C1d
C1b
C6d
The synthetic route for conversion of ethane to ethanol via ethene is
covered in section C6d.
Combustion of hydrocarbons is referred to in C1b, alkenes aren’t
mentioned.
Addition reactions and the formation of dibromo compounds is covered
in section C1d.
The reaction of alkenes with
oxygen, hydrogen, water and
halogens.
The displayed formulae for the
first four alkenes.
N/A
New AQA specification Current OCR specification
Specification reference:
4.7.2.3 Alcohols
Specification reference: C6d
The content is similar in both specifications:
names, formulae, functional group, structures and uses of
methanol and ethanol
combustion and reaction with sodium (Higher Tier only in OCR).
Propanol and butanol. Fermentation is covered in more
detail, including limits to the
concentration of ethanol produced
in fermentation and concentration
of the solution by distillation.
Comparison and evaluation of
fermentation and hydration as
production methods.
Specification reference:
4.7.2.4 Carboxylic acids
Specification reference:
C1g
C5g
C6g
The AQA specification is more detailed. The OCR specification refers to
their nature as weak acids (C5g), reaction with alcohols to produce
esters (C1g) and within the context of fats and oils (C6g).
Propanoic, butanoic and acids;
their structural formulae.
In item C1g the OCR specification
covers the properties and uses of
esters and a detailed method for
their preparation.
N/A Perfumes and animal testing of
cosmetics are covered in detail in
section C1g.
N/A Saponification using sodium
hydroxide is covered in section C6g
(both for Foundation and Higher
Tiers).
4.7.3 Synthetic and naturally occurring polymers
New AQA specification Current OCR specification
Specification reference:
4.7.3.1 Addition polymerisation
Specification reference: C1d
Both specifications cover polymerisation as the joining of many
monomers to form long chains.
OCR Higher Tier: drawing the displayed formula of an addition polymer.
Poly(ethene) and poly(propene). N/A
Specification reference:
4.7.3.2 Condensation
polymerisation
N/A
Specification reference:
4.7.3.3 Amino acids
This topic is not covered in the OCR
specification. However, proteins and
denaturation are mentioned in
cooking context (C1f).
Specification reference:
4.7.3.4 DNA and other naturally
occurring polymers
N/A
N/A Nylon and Gore-Tex as examples of
designer polymers (C1e).
Chemical analysis
4.8.1 Purity, formulations and chromatography
New AQA specification Current OCR specification
Specification reference:
4.8.1.1 Pure substances
Specification reference: C3g
Both specifications cover identification of pure substances based on
comparison of physical properties with less pure counterparts.
Definition of purity. N/A
Specification reference:
4.8.1.2 Formulations
This topic is not covered in the OCR
specification.
However, fuels, paints, alloys,
fertilisers and foods are referred to
in sections C1b, C3f and C6b (fuels),
New AQA specification Current OCR specification
C1h (paints), C2c and C2d (alloys),
C2g (fertilisers) and C1f (foods).
N/A The OCR specification details not
present in the AQA specification:
C1h - Paints and Pigments
C1f - Emulsifiers
C6g - Natural Fats and Oils
C6h - Detergents
Specification reference:
4.8.1.3 Chromatography
Specification reference:
C3g
C6h
The AQA specification is more detailed.
The OCR specification only refers to chromatography in terms of
extraction of chemicals from plants and elucidating the purity of a
substance through thin layer chromatography.
Solvents are discussed in other areas of the OCR specification without
reference to chromatography, eg in C1g, Smells and C1h, Paints and
Pigments
There is a required practical
investigating the chromatography
of coloured substances and
calculation of Rf values.
N/A
4.8.2 Identification of common gases
New AQA specification Current OCR specification
Specification reference:
4.8.2.1 Test for hydrogen
Specification reference: C6a
The content of both specifications is the same.
Specification reference:
4.8.2.2 Test for oxygen
Specification reference: C6a
The content of both specifications is the same.
New AQA specification Current OCR specification
Specification reference:
4.8.2.3 Test for carbon dioxide
Specification reference: C1f
Definition of limewater as an
aqueous solution of calcium
hydroxide.
N/A
Specification reference:
4.8.2.4 Test for chlorine
Specification reference: C2h
The content of both specifications is the same.
4.8.3 Identification of ions by chemical and spectroscopic means
New AQA specification Current OCR specification
Specification reference:
4.8.3.1 Flame tests
Specification reference: C4d
Both specifications require knowledge of flame tests and recollection of
flame colours for lithium, sodium and potassium.
Content includes flame colours for
calcium and copper.
N/A
Specification reference:
4.8.3.2 Metal hydroxides
Specification reference: C4f
Both specifications cover the precipitation of metal hydroxides as an
identification method for metal ions, although the list of ions is slightly
different.
N/A An understanding of precipitation in
the context of formation of an
insoluble compound.
Higher Tier: ionic equations for
precipitation reactions.
Specification reference:
4.8.3.3 Carbonates
N/A
Reactions of carbonates in terms of thermal decomposition and
reactions with acids are covered in several areas of the OCR
specification. Solubility in water is only mentioned in terms of water
hardness and calcium carbonate.
New AQA specification Current OCR specification
The pattern of solubility of
carbonates.
N/A
Specification reference:
4.8.3.4 Halides
Specification reference: C4h
The content of both specifications is the same.
Specification reference:
4.8.3.5 Sulfates
Specification reference: C4h
The content of both specifications is the same.
Specification reference:
4.8.3.6 Instrumental methods
N/A
General advantages of
instrumental methods.
N/A
Specification reference:
4.8.3.7 Flame emission
spectroscopy
N/A
Students are expected to interpret
a spectrum, given appropriate
data.
N/A
There is a required practical to
identify the ions in a single ionic
compound using the test tube
reactions.
N/A
Chemistry of the atmosphere
4.9.1 The composition and evolution of the Earth's atmosphere
New AQA specification Current OCR specification
Specification reference:
4.9.1.1 The proportions of
different gases in the atmosphere
Specification reference: C1c
The content of both specifications is very similar.
Specification reference:
4.9.1.2 The Earth's early
Specification reference:
C1.1.5 to 6
New AQA specification Current OCR specification
atmosphere C.1.1.8
The content of both specifications is almost the same.
A consideration of how theories
about the early atmosphere have
changed; limitations of the
evidence.
The presence of nitrogen,
methane and ammonia.
Higher Tier: detailed description of
atmospheric evolution.
Specification reference:
4.9.1.3 How oxygen increased
Specification reference: C1c
The content of both specifications is the same.
The chemical equation for
photosynthesis.
N/A
Specification reference:
4.9.1.4 How carbon dioxide
decreased
Specification reference: C1c
The content is similar, but the AQA specification goes into more detail
about the formation of limestone, coal and crude oil.
4.9.2 Carbon dioxide and methane as greenhouse gases
New AQA specification Current OCR specification
Specification reference:
4.9.2.1 Greenhouse gases
The mechanism of the greenhouse
effect in terms of radiation of
different wavelengths is not
covered in the OCR specification.
Specification reference:
4.9.2.2 Human activities which
contribute to an increase of
greenhouse gases in the
atmosphere
The increase of carbon dioxide and
methane in the atmosphere is not
covered in the OCR specification
except for a brief mention of carbon
dioxide as a greenhouse gas in C1b.
Specification reference:
4.9.2.3 Global climate change
The potential effects of climate
change are not covered in the OCR
specification.
New AQA specification Current OCR specification
Specification reference:
4.9.2.4 The carbon footprint and
its reduction
N/A
N/A Specification reference: C6e:
The OCR specification covers CFCs
and the depletion of the ozone layer
in detail.
4.9.3 Common atmospheric pollutants and their sources
New AQA specification Current OCR specification
Specification reference:
4.9.3.1 Atmospheric pollutants
from fuels
Specification reference:
C1b
C1c
The content is very similar in both specifications:
the formation of carbon dioxide, carbon monoxide, carbon, sulfur
dioxide and oxides of nitrogen
particulates.
Specification reference:
4.9.3.2 Properties and effects of
atmospheric pollutants
Specification reference:
C1b
C1c
Much of the content is the same:
carbon monoxide's effect on the blood
sulfur dioxide and oxides of nitrogen causing acid rain.
The effect of particulates on
global dimming. The respiratory
effects of particulates, sulfur
dioxide and oxides of nitrogen.
N/A
Using resources
4.10.1 Using the Earth's resources and obtaining potable water
New AQA specification Current OCR specification
Specification reference:
4.10.1.1 Using the Earth's
resources and sustainable
development
Not covered in the OCR
specification. However, ideas
regarding the use of chemistry to
improve processes can be found in
section C3e, Percentage Yield and
Atom Economy and C3g, Batch or
Continuous.
Similar ideas are covered in both specifications; both refer to natural
and synthetic materials, but use different examples.
The AQA specification refers to finite and renewable resources and to
sustainable development.
The OCR specification focuses on the properties of materials;
sustainability is developed in other areas throughout the specification.
N/A Specification reference: C2a
Earth's geology is covered in detail.
N/A The use of limestone as a building
material, including the production
of cement and concrete (C2b).
N/A The acquisition of salt and the
chlor-alkali industry are covered in
detail in C2h.
N/A Specification reference: C3a
The development of pharmaceutical
drugs and batch and continuous
production processes are covered in
detail.
Specification reference:
4.10.1.2 Potable water
Specification reference: C4h
The content of both specifications is very similar.
N/A Specification reference: C6f
Water hardness and its removal are
covered in detail.
Specification reference: N/A
New AQA specification Current OCR specification
4.10.1.3 Waste water treatment
Specification reference:
4.10.1.4 Alternative methods of
extracting metals
Phytomining and bioleaching is not
covered in the OCR specification,
except for copper extraction
mentioned in C2c.
4.10.2 Life cycle assessment and recycling
New AQA specification Current OCR specification
Specification reference:
4.10.2.1 Life cycle assessment
There is no reference to this
content in the OCR specification
although consideration is given to
the environmental impact of a
variety of chemical products,
particularly polymers, in C1e.
Specification reference:
4.10.2.2 Ways of reducing the use
of resources
Specification reference:
C1e
C2c to 2d
Both specifications cover recycling of metals and environmental impacts
of extracting metals. However, OCR specification does not consider other
materials. Recycling polymers is also considered at Higher Tier in the
OCR item C1e.
Reduction in use of materials and
reuse (for example of glass
bottles); recycling.
Resources also include glass,
building materials and ceramics.
The energy required coming from
limited resources.
N/A
4.10.3 Using materials
New AQA specification Current OCR specification
Specification reference:
4.10.3.1 Corrosion and its
prevention
Specification reference:
C2d
C6c
New AQA specification Current OCR specification
N/A Higher Tier: the disadvantages of
using tin plate for protection
against rusting.
Specification reference:
4.10.3.2 Alloys as useful materials
Specification reference: C2c
The content is very similar in both specifications, however they use
different examples.
AQA specification goes into more detail, eg the carat system for alloys of
gold.
Bronze, steel, gold alloys and
aluminium alloys.
Amalgam, brass and solder.
Specification reference:
4.10.3.3 Ceramics, polymers and
composites
Specification reference: C2b
The AQA specification goes into more detail and provides more
examples.
Glass, ceramics, composites and
polymers.
The specification includes the
properties of polymers depending
on the monomer used and the
conditions under which they are
made, using LDPE and HDPE as
examples. Polymers are classified
as thermo softening or
thermosetting.
Glass's relationship with sand and
brick's with clay.
There is no mention of low or high
density poly(ethene) or thermo
softening or thermosetting
polymers.
4.10.4 The Haber process and the use of NPK fertilisers
New AQA specification Current OCR specification
Specification reference:
4.10.4.1 The Haber process
Specification reference: C2e
The content is very similar in both specifications. The principles of
dynamic equilibrium are at Higher Tier in the AQA specification, but only
a simple explanation of the effect of changing temperature and pressure
is required at the same tier by OCR. The relationship between
commercially used conditions and cost/availability is referred to by both
New AQA specification Current OCR specification
specifications.
The removal of ammonia from the
reaction mixture by cooling.
A balanced symbol equation is used
at both tiers (although partly given
at foundation tier).
Specification reference:
4.10.4.2 Production and uses of
NPK fertilisers
Although the use of fertilisers is
covered in C2g, there is no
reference to the production of NPK
fertilisers.
N/A Eutrophication is covered in detail
in C2g.