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The Little Book of everything I need to know
for AS Chemistry in Year 12
General information
Unit 3 (coursework)
Assessment objectives
page
2
3
5
Scheme A
Targets and test record
Topic checklists
Unit 1
1.1 Atomic Structure
1.3 Bonding
1.4 Periodicity
Unit 2
2.10 Redox
2.11 Group 7
2.12 Group 2
2.13 Metal Extraction
2.8 Kinetics
2.9 Equilibria
Command words
How Science Works Words
Basic Standards of
Presentation and Marking
Laboratory Rules
Data sheet
Periodic table
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Scheme B
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Targets and test record
Topic checklists
Unit 1
1.2 Amount of Substance
1.5 Introduction to Organic
1.6 Alkanes
Unit 2
2.14 Haloalkanes
2.15 Alkenes
2.16 Alcohols
2.17 Analytical Techniques
2.7 Energetics
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General information
Exam Board: AQA
Text Book: AQA AS Chemistry; Ted Lister and Janet Renshaw
The most useful websites you will find: www.chemguide.co.uk and m.bestchoice.net.nz (for ipads) or
http://www.bestchoice.net.nz (for pc)
You also have access to all the resources on Kerboodle
AS Units:
Unit 1 – CHEM1
Foundation Chemistry
Examination paper (70 raw marks/100 UMS)
4 – 6 short answer questions plus 1 – 2 longer structured question(s).
1 hour 15 minutes
33 1/3 % of the total AS marks
16 2/3 % of the total A Level marks
Available in June only
Unit 2 – CHEM2
Examination paper (100 raw marks/140 UMS)
6 – 8 short answer questions plus 2 longer structured questions
1 hour 45 minutes
46 2/3 % of the total AS marks
23 1/3 % of the total A Level marks
Chemistry In Action
Available in June only
Unit 3 – Internal Assessment
Investigative and practical skills in AS Chemistry
CHM3T, Centre Marked Route
(50 raw marks/60 UMS)
Practical Skills Assessment (PSA – 12 raw marks)
Investigative Skills Assignment (ISA – 38 raw marks)
Topics:
Unit 1
1.1 Atomic Structure
1.2 Amount of substance
1.3 Bonding
1.4 Periodicity
1.5 Introduction to organic chemistry
1.6 Akanes
Unit 2
2.7 Energetics
2.8 Kinetics
2.9 Equilibria
2.10 Redox reactions
2.11 Group 7, the halogens
2.12 Group 2, the alkaline earth metals
2.13 The extraction of metals
2.14 Haloalkanes
2.15 Alkenes
2.16 Alcohols
2.17 Analytical techniques
2
Unit 3 – Internal Assessment
Throughout the course you will carry out experimental and investigative activities in order to develop
your practical skills. Experimental and investigative activities will allow you to use your knowledge and
understanding of Chemistry in planning, carrying out, analysing and evaluating your work. The
experience of dealing with such activities will develop the skills required for the assessment of these
skills in Unit 3.
In the course of your experimental work, you will learn to
• demonstrate and describe ethical, safe and skilful practical techniques
• process and select appropriate qualitative and quantitative methods
• make, record and communicate reliable and valid observations
• make measurements with appropriate precision and accuracy
• analyse, interpret, explain and evaluate the methodology, results and impact of their own and others’
experimental and investigative activities in a variety of ways.
These are all assessed as part of Unit 3. You MUST take ALL practical work seriously, in order to
develop the necessary skills to score highly in this Unit. This includes (but is not limited to)
recording observations appropriately, processing the results thoroughly (relating them to the
theory), and evaluating the validity of the results and method. The grade boundaries are VERY
high – so give yourself the best chance you can by preparing from the very first practical.
The practical and investigative skills will be centre assessed through:
Investigative Skills Assignment (ISA) [38 marks]
The ISA will require you to undertake practical work, collect and process data and use it to answer
questions in a written test (ISA test).
The ISA has two stages where you

Undertake practical work, collect andprocess data

Complete a written ISA test.
Stage 1: Collection and Processing of data
Candidates carry out practical work following an AQA task sheet. Candidates collect raw data and
represent it in a table of their own design or make observations that are recorded on the Candidate
Results Sheet. The candidates’ work must be handed to the teacher at the end of the session. The
teacher assesses the candidates’ work following AQA marking guidelines. There is no specified time
limit for this stage
The accuracy of your practical work is worth 8 marks (out of 38).
Stage 2: The ISA written test
The ISA test should be taken after completion of Stage 1, under controlled conditions. All candidates at a
centre must complete the written test in a single uninterrupted session on the same day. Each candidate
3
is provided with an ISA test and the candidate’s completed material from Stage 1. The teacher uses the
AQA marking guidelines to assess the ISA test.
The ISA test is in two Sections.


Section A
This consists of a number of questions relating to the candidate’s own data.
Section B
At the start of this section, candidates are supplied with additional data on a related topic. A
number of questions relating to analysis and evaluation of the data then follow.
The number of marks allocated to each section may vary slightly with each ISA test.
When you are told the topics for the ISA, you must revise them thoroughly – the written paper is
just like the Unit 1 and 2 papers – so think of it in that way.
The ISA is set externally by AQA, but internally marked, with marking guidelines provided by AQA.
Each stage of the ISA must be carried out under controlled conditions within the windows of assessment
stipulated by AQA
Practical Skills Assessment (PSA). [12 marks]
For the PSA you will be assessed throughout the course on your ability to follow and undertake certain
standard practical activities across the three areas of Chemistry: Inorganic, Organic and Physical.
Several practicals from each area will be assessed, with each scoring a mark of 0, 1 or 2. The best two
marks from each area will contribute to your PSA mark.
Assessment Descriptors
2 marks
1 mark
0 marks
Candidates are able to follow a set of instructions for the task in a safe and organised
way. Measurements are precise and within the expected range. Candidates require
minimal additional guidance to carry out the task in a competent manner and are able to
produce an outcome which is within the expected tolerance for the activity or produce a
set of results, most of which are correct.
Candidates are able to follow a set of instructions for the task in a reasonably safe way,
but could be better organised. Measurements are imprecise or outside the expected
range. Candidates require some additional guidance to carry out the task to a standard
which is considered appropriate and produce an outcome, which, whilst acceptable, may
not be within the expected tolerance for the activity or produce a set of results, only some
of which are correct.
Candidates have significant difficulty in following a set of instructions for the task and
their work is poorly organised or unsafe. Measurements are imprecise or outside the
expected range. Candidates require significant additional guidance to carry out the task
to a standard which is considered appropriate and produce an outcome which is
significantly outside the expected tolerance for the activity or produce a set of results,
few of which are correct.
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Assessment Objectives (AOs)
The Assessment Objectives are common to AS and A Level. The assessment units will assess the following
assessment objectives in the context of the content and skills set out in the specification.
AO1: Knowledge and understanding of Chemistry and of How Science Works
Candidates should be able to:
(a) recognise, recall and show understanding of scientific knowledge
(b) select, organise and communicate relevant information in a variety of forms.
AO2: Application of knowledge and understanding of Chemistry and of How Science Works
Candidates should be able to:
(a) analyse and evaluate scientific knowledge and processes
(b) apply scientific knowledge and processes to unfamiliar situations, including those related to issues
(c) assess the validity, reliability and credibility of scientific information.
AO3: How Science Works – Chemistry
Candidates should be able to:
(a) demonstrate and describe ethical, safe and skilful practical techniques and processes, selecting appropriate
qualitative and quantitative methods
(b) make, record and communicate reliable and valid observations and measurements with appropriate precision
and accuracy
(c) analyse, interpret, explain and evaluate the methodology, results and impact of their own and others’
experimental and investigative activities in a variety of ways.
Quality of written communication (QWC)
Candidates must:
 ensure that text is legible and that spelling, punctuation and grammar are accurate so that meaning is
clear
 select and use a form and style of writing appropriate to purpose and to complex subject matter
 organise information clearly and coherently, using specialist vocabulary where appropriate.
QWC will be assessed in all externally assessed units.
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Target grade: Date:………………… Grade: ………… Date:……………………Grade:..……
Topic
Test result Comment
Scheme A
1.1 Atomic structure
1.3 Bonding
1.4 Periodicity
2.10 Redox
2.11 Group 7
2.12 Group 2
2.13 Metal extraction
2.8 Kinetics
2.9 Equilibria
Targets
Due by
6
Done?
Targets (scheme A)
Due by
7
Done?
Topic
Test
result
Comment
Scheme B
1.2 Amount of substance
1.5 Introduction to organic chemistry
1.6 Alkanes
2.14 Haloalkanes
2.15 Alkenes
2.16 Alcohols
2.17 Analytical techniques
2.7 Energetics
Targets (scheme B)
Due by
8
Done?
Targets (scheme B)
Due by
9
Done?
Scheme A
Topic Checklist Atomic Structure 1.1
In Section 1.1 (Atomic Structure), you should gain
 a theoretical understanding of atomic structure.
 an understanding of how mass spectrometry is used to provide information about the existence
and relative abundance of isotopes.
 an insight into how electrons are arranged in main levels, sub-levels and atomic orbitals, through
the study of ionisation energy.
Fundamental particles
be able to describe the properties of protons, neutrons and electrons in terms of relative
charge and relative mass
know that early models of atomic structure predicted that atoms and ions with noble gas
electron-arrangements should be stable
Protons, neutrons and electrons
understand the importance of these particles in the structure of the atom and appreciate that
there are various models to illustrate atomic structure
Mass number and isotopes
be able to recall the meaning of mass number (A) and atomic (proton) number (Z)
be able to explain the existence of isotopes
understand the principles of a simple mass spectrometer, limited to ionisation, acceleration,
deflection and detection
know that the mass spectrometer gives accurate information about relative isotopic mass and
also about relative abundance of isotopes
be able to interpret simple mass spectra of elements and calculate relative atomic mass from
isotopic abundance, limited to mononuclear ions
know that mass spectrometry can be used to identify elements (as used for example in
planetary space probes)
know that mass spectrometry can be used to determine relative molecular mass
Electron arrangement
know the electron configurations of atoms and ions up to Z = 36 in terms of levels and sublevels (orbitals) s, p and d
know the meaning of the term ionisation energy.
understand how ionisation energies in Period 3 (Na – Ar) and in Group 2 (Be – Ba) give
evidence for electron arrangement in sub-levels and in levels
Key words
mass number (A)
atomic (proton) number (Z)
isotopes
Relative atomic mass
Relative molecular mass
Relative formula mass
Ionisation energy
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Scheme A
Topic Checklist Bonding 1.3
In Section 1.3 (Bonding), you should gain
 an in-depth understanding of bonding extending knowledge from GCSE.
 an understanding of intermolecular forces of attraction.
 an appreciation of the four types of crystal leading to a study of giant structures.an understanding
of the principles used to determine the shapes of simple molecules.
Nature of ionic, covalent and metallic bonds
understand that ionic bonding involves attraction between oppositely charged ions in a lattice
know that a covalent bond involves a shared pair of electrons
know that co-ordinate bonding is dative covalency
understand that metallic bonding involves a lattice of positive ions surrounded by delocalised
electrons
Bond polarity
understand that electronegativity is the power of an atom to withdraw electron density from a
covalent bond
understand that the electron distribution in a covalent bond may not be symmetrical
know that covalent bonds between different elements will be polar to different extents
Forces acting between molecules
understand qualitatively how molecules may interact by permanent dipole–dipole, induced dipole–
dipole (van der Waals’) forces and hydrogen bonding
understand the importance of hydrogen bonding in determining the boiling points of compounds
and the structures of some solids (e.g. ice)
States of matter
be able to explain the energy changes associated with changes of state
recognise the four types of crystal: ionic, metallic, giant covalent (macromolecular) and molecular
know the structures of the following crystals: sodium chloride, magnesium, diamond, graphite,
iodine and ice
be able to relate the physical properties of materials to the type of structure and bonding present
Shapes of simple molecules and ions
understand the concept of bonding and lone (non bonding) pairs of electrons as charge clouds
be able, in terms of electron pair repulsion, to predict the shapes of, and bond angles in, simple
molecules and ions, limited to 2, 3, 4, 5 and 6 co-ordination
know that lone pair/lone pair repulsion is greater than lone pair/bonding pair repulsion, which is
greater than bonding pair/bonding pair repulsion, and understand the resulting effect on bond
angles
Key words
co-ordinate bonding
dative covalency
hydrogen bonding
induced dipole–dipole (van der Waals’) forces
permanent dipole–dipole
covalent bond
Electronegativity: see above
ionic bonding
Metallic bonding
Scheme A
Scheme A
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Topic Checklist Periodicity 1.4
Classification of elements in s, p and d blocks
be able to classify an element as s, p or d block according to its position in the Periodic Table
Properties of the elements of period 3 to illustrate periodic trends
be able to describe the trends in atomic radius, first ionisation energy, melting and boiling points
of the elements Na – Ar
understand the reasons for the trends in these properties
Key words
s block element
p block element
d block element
Atomic radius
First ionisation energy
Unit 2
Topic Checklist Redox Reactions 2.10
Oxidation and reduction
know that oxidation is the process of electron loss
know that oxidising agents are electron acceptors
know that reduction is the process of electron gain
know that reducing agents are electron donors
Oxidation states
know and be able to apply the rules for assigning oxidation states in order to work out the
oxidation state of an element in a compound from its formula
understand oxidation and reduction reactions of s and p block elements
Redox equations
be able to write half-equations identifying the oxidation and reduction processes in redox
reactions when the reactants and products are specified
be able to combine half-equations to give an overall redox equation
Key words
Oxidation
Oxidising agent
Oxidation state (number)
Redox reaction
Reducing agent
Reduction
Scheme A
Scheme A
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Topic Checklist Group 7 (17) The Halogens 2.11
Trends in physical properties
understand the trends in electronegativity and boiling point of the halogens
Trends in the oxidising abilities of the halogens
understand that the ability of the halogens (from fluorine to iodine) to oxidise decreases down
the group (e.g. the displacement reactions with halide ions in aqueous solution)
Trends in the reducing abilities of the halide ions
understand the trend in reducing ability of the halide ions
know the different products formed by reaction of NaX and H2SO4
Identification of halide ions using silver nitrate
understand why acidified silver nitrate solution is used as a reagent to identify and distinguish
between F–, Cl–, Br – and I –
know the trend in solubility of the silver halides in ammonia
Uses of chlorine and chlorate(I)
know the reactions of chlorine with water and the use of chlorine in water treatment
appreciate that the benefits to health of water treatment by chlorine outweigh its toxic effects
know the reaction of chlorine with cold, dilute, aqueous NaOH and the uses of the solutions
formed
Key words
Oxidising ability (power)
electronegativity
Reducing ability (power)
Scheme A
Scheme A
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Topic Checklist Group 2, The Alkaline Earth Metals 2.12
Trends in physical properties
understand the trends in
 atomic radius,
 first ionisation energy and
 melting point
of the elements Mg – Ba
Trends in chemical properties
know the reactions of the elements Mg – Ba with water and recognise the trend
know the relative solubilities of the hydroxides of the elements Mg – Ba and that Mg(OH)2 is
sparingly soluble
know the use of
 Mg(OH)2 in medicine and of
 Ca(OH)2 in agriculture
know the relative solubilities of the sulfates of the elements Mg – Ba
understand why acidified BaCl2 solution is used as a reagent to test for sulfate ions
know the use of BaSO4 in medicine
Scheme A
Scheme A
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Topic Checklist The extraction of Metals 2.13
Principles of metal extraction
know that metals are found in ores, usually as oxides or sulfides and that sulfide ores are usually
converted into oxides by roasting in air
understand the environmental problems associated with the conversion of sulfides into oxides
and also that the sulfur dioxide produced can be used to manufacture sulfuric acid
understand that extraction of metals involves reduction
understand that carbon and carbon monoxide are cheap and effective reducing agents that are
used in the extraction of iron, manganese and copper (reduction equations and conditions only)
know why carbon reduction is not used for extraction of titanium, aluminium and tungsten
understand how aluminium is manufactured from purified bauxite (energy considerations,
electrode equations and conditions only)
understand how titanium is extracted from TiO2 via TiCl4 (equations and conditions only: either
Na or Mg as a reducing agent)
understand how tungsten is extracted from WO3 by reduction with hydrogen (equation,
conditions and risks only)
Environmental aspects of metal extraction
understand the environmental and economic advantages and disadvantages of recycling scrap
metals compared with the extraction of metals
understand the environmental advantages of using scrap iron to extract copper from aqueous
solutions compared with the high-temperature carbon reduction of copper oxide
know that the usual source of such aqueous solutions is low grade ore
Key words
Bauxite
Reduction
Ore
Scheme A
Scheme A
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Topic Checklist Kinetics 2.8
Collision theory

understand that reactions can only occur when collisions take place between particles
having sufficient energy

be able to define the term activation energy and understand its significance

understand that most collisions do not lead to reaction
Maxwell–Boltzmann distribution

have a qualitative understanding of the Maxwell–Boltzmann distribution of molecular
energies in gases

be able to draw and interpret distribution curves for different temperatures
Effect of temperature on reaction rate

understand the qualitative effect of temperature changes on the rate of reaction

understand how small temperature increases can lead to a large increase in rate
Effect of concentration

understand the qualitative effect of changes in concentration on rate of reaction
Catalysts

know the meaning of the term catalyst

understand that catalysts work by providing an alternative reaction route of lower
activation energy
Key words
activation energy
catalyst
Collision frequency
Collision theory
Homogeneous
Heterogeneous
Maxwell-Boltzmann distribution
Scheme A
Scheme A
16
Topic checklist Equilibria 2.9
The dynamic nature of equilibria
know that many chemical reactions are reversible
understand that for a reaction in equilibrium, although the concentrations of reactants and
products remain constant, both forward and reverse reactions are still proceeding at equal rates
Qualitative effects of changes of pressure, temperature and concentration on a system in
equilibrium
be able to use Le Chatelier’s principle to predict the effects of changes in temperature, pressure
and concentration on the position of equilibrium in homogeneous reactions
know that a catalyst does not affect the position of equilibrium
Importance of equilibria in industrial processes
be able to apply these concepts to given chemical processes
be able to predict qualitatively the effect of temperature on the position of equilibrium from the
sign of H for the forward reaction
understand why a compromise temperature and pressure may be used
know about the hydration of ethene to form ethanol and the reaction of carbon monoxide with
hydrogen to form methanol as important industrial examples where these principles can be
applied
know the importance of these alcohols as liquid fuels
Key words
Reversible reaction
Equilibria
Dynamic equilibrium
Le Chatelier’s Principle
Homogeneous
heterogeneous
H
Scheme A
Scheme A
17
Scheme B
Topic Checklist Amount of Substance 1.2
In Section1.2 (Amount of Substance) you should gain
 an understanding of the mole concept.
 an ability to apply the mole concept in circumstances which involve gases, solutions and solids.
 an ability to apply the mole concept to empirical formula analysis.
 an ability to use balanced equations.
 a range of manipulative skills in practical work associated with titrations.
Relative atomic mass and relative molecular mass
be able to define relative atomic mass (Ar) and relative molecular mass (Mr) in terms of 12C.
(The term relative formula mass will be used for ionic compounds)
The mole and the Avogadro constant (L)
understand the concept of a mole as applied to electrons, atoms, molecules, ions, formulae
and equations
understand the concept of the Avogadro constant. (Calculation not required)
The ideal gas equation
be able to recall the ideal gas equation pV = nRT and be able to apply it to simple calculations
in S.I. units, for ideal gases
Empirical and molecular formulae
understand the concept of and the relationship between empirical and molecular formulae
be able to calculate empirical formulae from data giving percentage composition by mass
Balanced equations and associated calculations
be able to write balanced equations (full and ionic) for reactions studied
be able to balance equations for unfamiliar reactions when reactants and products are
specified. (This is an important skill that applies in all modules)
be able to calculate reacting volumes of gases
be able to calculate concentrations and volumes for reactions in solutions, limited to titrations
of monoprotic acids and bases and examples for which the equations are given.
know that % atom economy = (mass of desired product / total mass of reactants) x100
be able to calculate reacting masses, % yields and % atom economies from balanced
equations
Key words
Avogadro constant
Empirical formula
Ideal gas
Molecular formula
mole
Monoprotic
Percentage (%) atom economy
Percentage (%) yield
relative atomic mass (Ar)
relative formula mass
relative molecular mass (Mr)
Scheme B
Scheme B
18
Topic Checklist Introduction to Organic Chemistry 1.5
Nomenclature
know and understand the terms
 empirical formula,
 molecular formula,
 structural formula,
 displayed formula,
 homologous series and
 functional group
be able to apply IUPAC rules for nomenclature to simple organic compounds, limited to
chains with up to 6 carbon atoms limited in this module to alkanes, alkenes and
haloalkanes
Isomerism
know and understand the meaning of the term structural isomerism
be able to draw the structures of chain, position and functional group isomers
Introduction to Organic
Chemistry 1.5
empirical formula
molecular formula
structural formula
displayed formula
homologous series
functional group
IUPAC
alkanes
alkenes
haloalkanes
Structural isomerism
Chain isomerism
Positional isomerism
functional group isomerism
The simplest whole number ratio in which the atoms in a compound
combine together
The formula giving the numbers of atoms of each different element tin a
molecule of the compound e.g. butan-2-ol is C4H10O
A way of writing the formula of an organic compound in which bonds are
not shown but each carbon atom is written separately with the atoms or
group of atoms attached to it e.g. butan-2-ol is CH3CH(OH)CH2CH3
The formula of a compounds drawn out to show all the atoms and all the
bonds e.g. butan-1-ol is
A family of organic compounds with the same functional group, but
different chain length
An atom or group of atoms in an organic molecule that is responsible for
the characteristic reactions that the molecule undergoes.
The International Union of Pure and Applied Chemistry
Saturated hydrocarbons with general formulae CnH2n+2
Unsaturated hydrocarbons with general formula CnH2n
Alkanes in which one or more hydrogen atom has been replaced with a
halogen atom
Molecules with the same molecular formula but different structural
formulae
A different arrangement of the hydrocarbon chain e.g. branching
[a form of structural isomerism]
The functional group is attached to the main chain at different positions
[a form of structural isomerism]
The functional groups are different [a form of structural isomerism]
Scheme B
Scheme B
19
Topic Checklist Alkanes 1.6
Fractional distillation of crude oil
know that alkanes are saturated hydrocarbons
know that petroleum is a mixture consisting mainly of alkane hydrocarbons
understand that different components (fractions) of this mixture can be drawn off at different
levels in a fractionating column because of the temperature gradient
Modification of alkanes by cracking
understand that cracking involves the breaking of C–C bonds in alkanes
know that thermal cracking takes place at high pressure and high temperature and produces a
high percentage of alkenes (mechanism not required)
know that catalytic cracking takes place at a slight pressure, high temperature and in the
presence of a zeolite catalyst and is used mainly to produce motor fuels and aromatic
hydrocarbons (mechanism not required)
understand the economic reasons for the cracking of alkanes (e.g. ethene used for poly(ethene);
conversion of heavy fractions into higher value products)
Combustion of alkanes
know that alkanes are used as fuels and understand that their combustion can be complete or
incomplete and that the internal combustion engine produces a number of pollutants (e.g. NOx,
CO and unburned hydrocarbons)
know that these pollutants can be removed using catalytic converters
know that combustion of hydrocarbons containing sulfur leads to sulfur dioxide that causes air
pollution and understand how sulfur dioxide can be removed from flue gases using calcium oxide
know that the combustion of fossil fuels (including alkanes) results in the release of carbon
dioxide into the atmosphere
know that carbon dioxide, methane and water vapour are referred to as greenhouse gases and
that these gases may contribute to global warming
The harmful effects that pollutants (e.g. NOx, CO and unburned hydrocarbons) could have on
the environment and how chemistry is used to reduce their release
Discuss critically the issues which surround the role of H2O, CH4 and CO2 as greenhouse gases
Alkanes 1.6
Hydrocarbon
Alkane
Saturated hydrocarbon
petroleum
Fraction
Fractional distillation
cracking
Catalytic cracking
Thermal cracking
zeolite
aromatic hydrocarbons
Catalytic converter
Complete combustion
Incomplete combustion
Greenhouse gas
Global warming
Compounds containing hydrogen and carbon only
Saturated hydrocarbons with general formulae CnH2n+2
Compound of only carbon and hydrogen containing only single bonds
Mixture of hydrocarbons
Mixture of hydrocarbons with similar boiling points
Separation of components because of differing boiling points
Breaking down large hydrocarbons into smaller alkanes and alkenes
Compounds containing the benzene ring [benzene: C6H6]
Combustion in which all elements undergo complete oxidation
Combustion in which
Scheme B
Scheme B
20
Unit 2
Topic Checklist Haloalkanes 2.14
Synthesis of chloroalkanes
understand the reaction mechanism of methane with chlorine as a free-radical substitution
reaction in terms of initiation, propagation and termination steps
Know that chloroalkanes and chlorofluoroalkanes can be used as solvents
understand that ozone, formed naturally in the upper atmosphere is beneficial
be able to use equations such as the following to explain why chlorine atoms catalyse the
decomposition of ozone and contribute to the formation of a hole in the ozone layer
Cl• + O3 → ClO• + O2
and
ClO• + O3 → 2O2 + Cl•
know that chlorine atoms are formed in the upper atmosphere when energy from ultra-violet
radiation causes C–Cl bonds in chlorofluorocarbons (CFCs) to break
appreciate that legislation to ban the use of CFCs was supported by chemists and that they have
now developed alternative chlorine-free compounds
Nucleophilic substitution
understand that haloalkanes contain polar bonds
understand that haloalkanes are susceptible to nucleophilic attack, limited to OH
NH3
–
, CN
–
and
understand the mechanism of nucleophilic substitution in primary haloalkanes
understand that the carbon–halogen bond enthalpy influences the rate of hydrolysis
appreciate the usefulness of these reactions in organic synthesis
Elimination
understand concurrent substitution and elimination (including mechanisms) in the reaction of a
haloalkane (e.g. 2- bromopropane with potassium hydroxide) and the role of the reagent as both
nucleophile and base appreciate the usefulness of this reaction in organic synthesis
Key words
free-radical
Free-radical substitution
initiation
hydrolysis
mechanism
nucleophile
Nucleophilic substitution
ozone
Primary haloalkane
propagation
Secondary haloalkane
substitution
termination
Tertiary haloalkane
Scheme B
Scheme B
21
Topic Checklist Alkenes 2.15
Alkenes: structure, bonding and reactivity
know that alkenes are unsaturated hydrocarbons
know that bonding in alkenes involves a double covalent bond
know that the arrangement >C=C< is planar
know that the alkenes can exhibit E-Z stereoisomerism
 be able to draw the structures of E and Z isomers
 understand that E-Z isomers exist due to restricted rotation about the C=C bond
understand that the double bond in an alkene is a centre of high electron density
Addition reactions of alkenes
understand the mechanism of electrophilic addition of alkenes with HBr, H2SO4 and Br2
know that bromine can be used to test for unsaturation
be able to predict the products of addition to unsymmetrical alkenes by reference to the relative
stabilities of primary, secondary and tertiary carbocation intermediates
understand that alcohols are produced industrially by hydration of alkenes in the presence of an
acid catalyst.
know the typical conditions for the industrial production of ethanol from ethene
Polymerisation of alkenes
know how addition polymers are formed from alkenes
recognise that poly(alkenes) like alkanes are unreactive
be able to recognise the repeating unit in a poly(alkene)
know some typical uses of poly(ethene) and poly(propene) and know that poly(propene) is
recycled
Key words
Addition polymerisation
Alkene
Biodegradable
carbocation
Electrophile
Electrophilic addition
E-Z isomers
Hydration (of alkenes)
intermediate
Primary carbocation
Repeat unit
Secondary carbocation
Stereoisomerism
Tertiary carbocation
Unsaturated hydrocarbon
Unsymmetrical
Scheme B
Scheme B
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Topic Checklist Alcohols 2.16
Nomenclature
be able to apply IUPAC rules for nomenclature to alcohols, aldehydes, ketones and carboxylic
acids limited to chains with up to 6 carbon atoms
Ethanol production
know how ethanol is produced industrially by fermentation know the conditions for this reaction
and understand the economic and environmental advantages and disadvantages of this process
compared with the industrial production from ethene
understand the meaning of the term biofuel
know that the term carbon neutral refers to ‘an activity that has no net annual carbon
(greenhouse gas) emissions to the atmosphere’
appreciate the extent to which ethanol, produced by fermentation, can be considered to be a
carbon-neutral biofuel
Classification and reactions
understand that alcohols can be classified as primary, secondary or tertiary
understand that tertiary alcohols are not easily oxidised
understand that primary alcohols can be oxidised to aldehydes and carboxylic acids and that
secondary alcohols can be oxidised to ketones by a suitable oxidising agent such as acidified
potassium dichromate(VI) (equations showing [O] as oxidant are acceptable)
be able to use a simple chemical test to distinguish between aldehydes and ketones (e.g.
Fehling’s solution or Tollens’ reagent)
Elimination
know that alkenes can be formed from alcohols by acid catalysed elimination reactions
(mechanism not required)
appreciate that this method provides a possible route to polymers without using monomers
derived from oil
Key words
alcohols
aldehydes
biofuel
carbon neutral
carboxylic acids
elimination
Fehling’s solution
fermentation
ketones
Tollens’ reagent
2,4-DNPH
Scheme B
Scheme B
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Topic Checklist Analytical Techniques 2.17
Mass spectrometry
understand that high resolution mass spectrometry can be used to determine the molecular
formula of a compound from the accurate mass of the molecular ion
Infrared spectroscopy
understand that certain groups in a molecule absorb infrared radiation at characteristic
frequencies
understand that ‘fingerprinting’ allows identification of a molecule by comparison of spectra
be able to use spectra to identify particular functional groups and to identify impurities, limited to
data presented in wave- number form
understand the link between absorption of infrared radiation by bonds in CO2, methane and
water vapour and global warming
Key words
‘Fingerprinting’
high resolution mass
spectrometry
infrared radiation
Infrared spectroscopy
Mass spectrometry
molecular ion
Scheme B
Scheme B
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Topic Checklist Energetics 2.7
Enthalpy change (H)
know that reactions can be endothermic or exothermic
understand that enthalpy change (H) is the heat energy change measured under conditions of
constant pressure
know that standard enthalpy changes refer to standard conditions, i.e. 100 kPa and a stated
temperature (e.g. H298)
Be able to recall the definition of standard enthalpies of combustion (Hc ) and formation (Hf )
Calorimetry
be able to calculate the enthalpy change from the heat change in a reaction using the equation
q = mc T
Simple applications of Hess’s Law
know Hess’s Law and be able to use it to perform simple calculations, for example calculating
enthalpy changes for reactions from enthalpies of combustion or enthalpies of formation
Bond enthalpies
be able to determine mean bond enthalpies from given data be able to use mean bond
enthalpies to calculate a value of H for simple reactions
Key words
bond enthalpy
endothermic
exothermic
enthalpy change (H)
the heat energy change measured under conditions of constant
pressure
Hess’s Law
mean bond enthalpy
standard conditions
standard enthalpy of combustion
(Hc )
standard enthalpy of formation
(Hf )
100 kPa and a stated temperature (e.g. H298)
Scheme B
Scheme B
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Command words
For examples of how to answer these types of questions, see the separate booklet on Firefly.
Calculate
You should use numbers given in the question to work out the answer.
As stated on the front of the paper, you should always show their working, as it may be possible for the examiner
to award some marks for the method even if the final answer is wrong.
You should always give the units when asked to do so. In the question a mark can be awarded for the correct
unit/units, even if the calculation is wrong.
Compare
This requires you to describe the similarities and/or differences between things, not just write about one.
If you are asked to ‘compare x with y’, you need to write down something about x compared to y, using
comparative words such as ‘better, ‘more than’, ‘less than’, ‘quicker’, ‘more expensive’, ‘on the other hand.’
Complete
Answers should be written in the space provided, eg on a diagram, in spaces in a sentence or in a table.
Describe
You may be asked to recall some facts, events or process in an accurate way. For example you may be asked to
describe an experiment you have done, or you may need to give an account of what something looked like, or
what happened, eg a trend in some data.
Evaluate
You should use the information supplied as well as your knowledge and understanding to consider evidence for
and against. An evaluation goes further than ‘compare’. For example, you may be given a passage to read and
told to ‘Evaluate the benefits of using system x and system y’. This means you will need to write down some of
the points for and against both systems to develop an argument. A mark may also be available for a clear and
justified conclusion. For example, if a question is worth 5 marks, and does not specifically ask for a conclusion,
then you can gain all 5 marks for 5 valid points made for and against. If you only make 4 points but give a justified
conclusion then the 5th mark can be gained.
However, if a question specifically asks for a justified conclusion then full marks can only be gained if a justified
conclusion is given.
When giving comparisons you should be encouraged to compare both sides using linking words. For example in a
physics question ‘Wind power is a renewable resource whereas fossil fuels are non-renewable.’ Useful words to
use could be ’however’, ‘whereas’ ‘but’ and ’on the other hand’.
No credit will be given just for giving the information stated directly from the question in either the comparisons
or in the conclusion. In the chemistry example a mark is given for ‘waste’ oils being able to be used whereas just
saying ‘vegetable’ oils can be used would not gain a mark.
Likewise there would be no mark for stating that biodiesel produces fewer carbon particles, but a mark is
awarded for linking this to less global dimming.
Explain
You should make something clear, or state the reasons for something happening.
The answer should not be a simple list of reasons.
This means that points in the answer must be linked coherently and logically. Suitable linking words could be ‘so’,
‘therefore’, ‘because’, ‘due to’, ‘since’, ‘this means’ or ‘meaning that’.
All of the stages/steps in an explanation must be included to gain full marks.
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State, give, name, write down
Only a short answer is required, not an explanation or a description. Often it can be answered with a single word,
phrase or sentence.
If the question asks you to state, give, or write down one (or two etc) examples, you should write down only the
specified number of answers, or you may not be given the mark for some correct examples given.
Suggest
This term is used in questions where you need to apply your knowledge and understanding to a new situation.
Often there may be more than one correct answer as you are expected to base your answers on scientific
knowledge and/or principles.
Useful words to use are ‘may’, ‘might’, ‘could’, and ‘I think that’.
Use the information in the passage/diagram/graph/table to…
The answer must be based on the information given in the question. Unless the information given in the question
is used, no marks can be given.
In some cases you might be asked to use your own knowledge and understanding and credit will be given.
How Science Works Key Words
Word / Phrase
Accuracy
Calibration
Meaning
A measurement result is considered accurate if it is judged to be close to
the true value
Marking a scale on a measuring instrument. This involves establishing
the relationship between indications of a measuring instrument and
standard or reference quantity values, which must be applied. For
example, placing a thermometer in melting ice to see whether it reads
zero, in order to check if it has been calibrated correctly
Data
Information, either qualitative or quantitative, that has been collected
Errors
See also uncertainties
- measurement error
The difference between a measured value and the true value
- anomalies
- random error
- systematic error
- zero error
These are values in a set of results which are judged not to be part of the
variation caused by random uncertainty.
These cause readings to be spread about the true value, due to results
varying in an unpredictable way from one measurement to the next.
Random errors are present when any measurement is made, and cannot
be corrected. The effect of random errors can be reduced by making
more measurements and calculating a new mean.
These cause readings to differ from the true value by a consistent
amount each time a measurement is made. Sources of systematic error
can include the environment, methods of observation or instruments
used. Systematic errors cannot be dealt with by simple repeats. If a
systematic error is suspected, the data collection should be repeated
using a different technique or a different set of equipment, and the
results compared
Any indication that a measuring system gives a false reading when the
true value of a measured quantity is zero, eg the needle on an ammeter
failing to return to zero when no current flows. A zero error may result in
a systematic uncertainty
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Evidence
Data which has been shown to be valid
Fair test
A fair test is one in which only the independent variable has been
allowed to affect the dependent variable.
Hypothesis
A proposal intended to explain certain facts or observations
Interval
Precision
Prediction
Range
Repeatable
Reproducible
Resolution
Sketch graph
True value
Uncertainty
Validity
Valid conclusion
Variables
- categoric
- continuous
- control
- dependent
- independent
The quantity between readings, eg a set of 11 readings equally spaced
over a distance of 1 metre would give an interval of 10 centimetres.
Precise measurements are ones in which there is very little spread about
the mean value. Precision depends only on the extent of random errors –
it gives no indication of how close results are to the true value.
A prediction is a statement suggesting what will happen in the future,
based on observation, experience or a hypothesis.
The maximum and minimum values of the independent or dependent
variables; important in ensuring that any pattern is detected. For
example a range of distances may be quoted as either: "From 10cm to 50
cm" or "From 50 cm to 10 cm"
A measurement is repeatable if the original experimenter repeats the
investigation using same method and equipment and obtains the same
results
A measurement is reproducible if the investigation is repeated by
another person, or by using different equipment or techniques, and the
same results are obtained.
This is the smallest change in the quantity being measured (input) of a
measuring instrument that gives a perceptible change in the reading.
A line graph, not necessarily on a grid, that shows the general shape of
the relationship between two variables. It will not have any points
plotted and although the axes should be labelled they may not be scaled
This is the value that would be obtained in an ideal measurement
The interval within which the true value can be expected to lie, with a
given level of confidence or probability, eg “the temperature is 20 °C ± 2
°C, at a level of confidence of 95 %.
Suitability of the investigative procedure to answer the question being
asked. For example, an investigation to find out if the rate of a chemical
reaction depended upon the concentration of one of the reactants
would not be a valid procedure if the temperature of the reactants was
not controlled.
A conclusion supported by valid data, obtained from an appropriate
experimental design and based on sound reasoning.
These are physical, chemical or biological quantities or characteristics
Categoric variables have values that are labels. Eg names of plants or
types of material
Continuous variables can have values (called a quantity) that can be
given a magnitude either by counting (as in the case of the number of
shrimp) or by measurement (eg light intensity, flow rate etc).
A control variable is one which may, in addition to the independent
variable, affect the outcome of the investigation and therefore has to be
kept constant or at least monitored.
The dependent variable is the variable of which the value is measured
for each and every change in the independent variable
The independent variable is the variable for which values are changed or
selected by the investigator
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Basic Standards of Presentation and Marking
Presentation
 All work is to have a title describing what it is about (not just ‘Prep ‘or ‘Classwork’).
 All work is to be dated.
 Headings and dates are to be underlined with a ruler in the same colour as the writing ink
used.
 A line space is to be left after the heading and date.
 Tippex or other correcting fluid must not be used; a neat, single straight line through the
incorrect word is all that is required.
Spelling
 Key spelling errors will be identified and the correct spelling written out by your teacher
for guidance.
 Science text books contain spelling lists of essential vocabulary.
Diagrams
 These need to be drawn in pencil.
 Any shading is to be done neatly using coloured pencils, if appropriate.
 Labeling should be done in ink.
 Labeling and headings must be able to be read while looking at the diagram and without
having to turn the paper.
 If arrows or lines are needed to connect the labels with the diagram, they should be
drawn in pencil with a ruler.
Graphs and tables
 All graphs and tables are to be drawn in pencil.
 Tables are to be titled and boxed in, have the independent variable in the first column
and only have units in the headings.
 Graphs are to be titled and have the independent variable along the x axis.
 Axes should be labeled and have units e.g. Time (seconds)
 Bar charts are to be used for discontinuous data, while line graphs are to be used for
continuous data.
Technical writing errors
The following indicators are used:
 sp and the underlining of a misspelling
 p to indicate incorrect or missing punctuation
 exp to indicate inaccurate expression with a wiggly line under the relevant area, or down
the margin.
 gr to indicate an area of inaccurate grammar, with a wiggly line under the relevant area,
or down the margin.
 ^ to show where a word, phrase or key point is missing.
Target setting
 T or
indicates a target for you to work on in future pieces of work.
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RHS Chemistry Department - Laboratory Rules
The Health and Safety at Work Act holds teachers and pupils responsible for their actions if others are harmed by them.
The biggest danger in the laboratory is YOU!
You are a danger whenever you are either thoughtless or careless or both.
Remember this, because the person most likely to suffer from your mistakes is YOU!
1.
You should only go into a lab if you have permission to do so from a teacher.
2.
You must wear eye protection when told to do so and at all times during Chemistry practical
work and keep it on until all practical work (including tidying up) is finished.
3.
Long hair must be tied back and loose garments should be tucked in before any experiment.
4.
Never put anything in your mouth (food or drink) in the lab. This includes fingers and pencils.
5.
You must not be seated during experimental work, unless you are specifically told to do so by
your teacher.
6.
If you are not sure of what you are supposed to do during a practical ASK for help.
7.
Don't touch apparatus, electrical equipment or chemicals (or gas taps, water taps and
electricity supplies) unless you have been told to do so.
8.
When heating substances, use small amounts and take care not to point test tubes at yourself
or anybody else, and never look directly down a test tube.
9.
Only place hot objects on a heat proof mat using appropriate apparatus. Allow hot equipment
or substances to cool before you touch them, store them or throw them away.
10. If you get burnt, or get chemicals on your skin, immediately wash the affected part with lots of
cold water and alert your teacher.
11. Report ANY accident, however slight (including breakages and spillages), to your teacher.
12. Waste, or surplus, materials should be disposed of as instructed by your teacher.
DON'T throw solids into sinks.
13. Keep your bench clean and tidy. Make sure it is wiped clean at the end of any experiment.
14. Wash your hands after laboratory work; this is especially important before meals.
15. Apparatus and chemicals must NEVER be removed from a lab.
ANY INAPPROPRIATE OR DANGEROUS BEHAVIOUR WILL
RESULT IN EXCLUSION FROM PRACTICAL ACTIVITIES.
I have read and understood the laboratory rules listed above.
Name:______________________________________________
Form: _______________
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