Elements of Life (EL) – Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas. Notes EL – Section 1 – (a), (g), (h), (x) The Big Bang theory is used to introduce the question of where the elements come from. This leads to discussion of the concepts of atomic structure, nuclear fusion, and the use of mass spectroscopy to determine the relative abundance of isotopes. 3 hours Research and evaluate the evidence on the formation of elements and the development of the atomic structure (HSW1, 6, 7) - a good opportunity for developing presentation skills and peer-assessment. will provide opportunities for practice. Main chemical atomic structure; fusion reactions; mass spectroscopy and isotopes. Interpretation of data from mass spectrometry is required, but not the workings of the instruments. Knowledge of nuclear fission is no longer required. Note that the specification periodic now follows , showing atomic number at the top and relative atomic mass at the bottom of each element. A ‘print-your-own’ A1 sized OCR Periodic Table is available .
EL – Section 2 – (e), (f), (i), (j), (k), (m), (n), (v), (w) Next, looking at how we study the radiation we receive from outer space provides the context for discussion of atomic spectroscopy and electronic structure. A historical approach is used to introduce the periodic table, including the links between electronic structure and physical properties. This is followed by studying some of the molecules found in space, providing the context for introducing bonding and structure and the shapes of molecules. 14 hours out flame tests with compounds containing appropriate ions – for example . Atomic and molecular structure provides opportunities for building and discussion (HSW1, 8). Explanation of atomic spectra in of electron transitions and the use of ‘dot-and-cross’ diagrams in explaining molecular shape provide opportunities for discussing development of scientific arguments (HSW2). Deducing electronic configurations through identification of relationships between ionisation enthalpy and atomic number provides opportunities for analysis and interpretation of data (HSW5). Main chemical ideas: Atomic spectra and electron configuration; the periodic table and Group 2 chemistry; Bonding and shapes of molecules. 2.8.8 notation is no longer required. Detailed discussion of atomic and electronic structure, including s and p orbital shapes, are studied here. The electrostatic nature of covalent bonding and lone pair effects in molecular shapes are now discussed. Giant metallic, ionic and covalent-lattice structures are introduced. Flames tests are included. Knowledge of the EM spectrum from infrared to ultraviolet is required, and use of both c = and E = h. Group numbers now following (1 to 18), i.e. halogens are referred to as Group 17 and noble gases as Group 18.
DF – Section 1 – (a), (d), (f), (g) The use of in cars provides the main context in this storyline, and is used to initially introduce the basic concept of enthalpy change. Food as ‘fuel’ for the body is then an alternative context in which to discuss quantitative aspects of enthalpy, including practical techniques and enthalpy cycles. 9 hours PAG 3 – Enthalpy determination (experiments to measure the energy transferred when reactions occur in solution or when flammable liquids burn). Calculation of enthalpy changes from experimental techniques (HSW2). Main chemical thermochemistry A statement of Hess' law is not required, but calculations using the law are. Molar gas volume and the gas constant are given on the . Molar volume is given to three significant figures (24.0 dm3 mol–1 at RTP), and the gas constant to four significant figures (8.314 J mol–1 K–1). Accurate use of the following terms will be required: exothermic, endothermic, standard conditions, (standard) enthalpy change of reaction (rH), (standard) enthalpy change of combustion (cH), (standard) enthalpy change of formation (fH), (standard) enthalpy change of neutralisation (neutH).
DF – Section 2 – (e), (h), (i), (j), (l), (m), (r) The storyline returns to the constituents of car fuels to introduce hydrocarbons and bond enthalpy, after which cracking provides the background to how petrol is produced. 6 hours Catalytic cracking of paraffin offers opportunities for development of risk assessments and manipulative skills – for example . Main chemical ideas: organic chemistry: names and combustion of alkanes and alcohols. Accurate use of the following will be required: average bond enthalpy, catalyst, catalysis, catalyst poison, heterogeneous, cracking, aliphatic, aromatic, arene, saturated, unsaturated, functional group and homologous series. Octane numbers and the effect of isomerisation, reforming and cracking on hydrocarbon performance do not need to be discussed. Arenes can be represented as the 'delocalised electron' model or the 'polyene' model.
DF Section 3 – (d), (m), (o), (p), (q) Alkenes are then introduced in the context of saturated and unsaturated fats found in foods. This is followed by studying the polymerisation of alkenes in the context of synthetic polymers and their uses. 6 hours PAG 7 – Qualitative analysis of organic functional groups (testing compounds for unsaturation using bromine water). Main chemical ideas: organic chemistry: names and combustion of alkenes; heterogeneous catalysis; reactions of alkenes; addition polymers; electrophilic addition. Accurate use of the following terms will be required: addition, electrophile, carbocation. Discussion of bonding now includes ideas of sigma and pi bonding. Discussion of reactions (including mechanisms) and isomerisation of alkenes, and formation of polymers are discussed here.
DF – Section 4 – (a), (c), (k), (n), (s), (t), (u) The storyline returns to car fuels to discuss combustion reactions and amount of substance calculations involving gases, shapes of hydrocarbons and isomerism, and the atmospheric pollutants produced in burning fuels. The storyline ends by considering the contribution of hydrogen and biofuels as potential fuels of the future. 8 hours PAG 1 – Moles determination (experiments involving volumes of gas). Considering the benefits and risks of using fossil fuels and alternative fuels (HSW9). Considering the environmental implications of atmospheric pollutants and extracting minerals from the (HSW10). Main chemical ideas: organic chemistry: names and combustion of alcohols; gas volume calculations; shapes of organic molecules (- and -bonds); structural and E/Z isomers (CIP rules not required); dealing with polluting gases. The ideal gas equation should be taught. Particular emphasis should be placed on accurate use of units and plenty of practice is required. Entropy has been to 2nd year study, but may be worth mentioning now for those requiring stretch-and-challenge. Elements from the Sea (ES) – Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas.
ES – Section 3 – (a), (l), (m), (q) Finally, atom economy is introduced through the manufacture of hydrogen chloride and other hydrogen halides. The Deacon process for making HCl provides an opportunity to expand on ideas relating to the position of equilibrium. 4 hours Demonstrate the reactions of concentrated sulfuric acid on sodium chloride, bromide and iodide to produce hydrogen halides. Reaction of these gases with ammonia demonstrates their acidic nature. Their thermal stability with a red-hot glass rod can also be demonstrated. Using experimental observations to explain the reactions between sodium halides and concentrated sulfuric acid (HSW5). Main chemical ideas: Halogen chemistry; equilibrium; atom economy. Reactions of sulfuric acid with hydrogen halides should be carefully discussed. The Ozone Story (OZ) – Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas.
OZ – Section 2 – (e), (f), (g), (h), (i), (o), (p), (q), (r), (s), (t), (u) Discussion of ozone‘s role as a ‘sunscreen’ then leads to ideas of the principal types of electromagnetic radiation and their effects on molecules. This introduces a study of radical reactions, reaction kinetics and catalysis, set in the context of the ways in which ozone is made and destroyed in the atmosphere. 9 Experiments involving alkanes and bromine – for example . Experiments on reaction kinetics – for example . Using collision theory to explain rates (HSW1). Main chemical ideas: The electromagnetic spectrum and the interaction of radiation with matter; rates of reaction; radical reactions. Accurate use of the following terms will be required: activation enthalpy and homogeneous catalysis. Greenhouse effect has moved to Oceans. Discussion of gases of the atmosphere, evidence of ozone depletion, properties, advantages and disadvantages of CFCs and research leading to the discovery of the ozone hole are not required. Recall of control of CO2 is not required. The specific structures of diamond, CO2 and SiO2 are not in the specification, but these may be used as contexts in AO2 questions. Boltzmann distribution has been introduced - discuss the construction and interpretation of the its modification with temperature, and how changes in rate with temperature and catalysts can be interpreted with respect to Ea and the distribution. Ea is related to the energy of pairs of molecules.
Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas. WM – Section 1 – (a), (b), (c), (d), (f), (h) A consideration of medicines from nature focuses on aspirin. The chemistry of the –OH group is introduced through reactions of salicin and salicylic acid, beginning with alcohols and continuing with phenols. 12 hours PAG 5 – Synthesis of an organic liquid (principal stages in the purification of an organic liquid product by preparing a chloroalkane). PAG 7 – Qualitative analysis of organic functional groups. Experiments involving reactions of the OH Experiments to oxidise alcohols – for example . To prepare an organic compound involving the process of heating under reflux. Main chemical ideas: Chemistry of the OH group, phenols and alcohols, carboxylic acids and esters. Accurate use of the following terms will be required: elimination reaction.
WM – Section 2 – (i), (j) The discussion of chemical for alcohols and phenols leads to the introduction of IR and mass spectrometry as more powerful methods for identifying substances. 3 hours will provide opportunities for practice. Main chemical ideas: Mass spectrometry and infrared spectroscopy. IR absorptions are given on the . Calculations based on the M+1 peak are not required. WM – Section 3 – (e), (g) The storyline concludes by examining the synthesis of aspirin to illustrate organic preparative techniques, including a look at the principles of green chemistry. 6 hours PAG 6 – Synthesis of an organic solid. Experiments to synthesise and purify an organic compound, determining melting point and running a TLC, e.g. aspirin synthesis – for example . Main chemical ideas: organic synthesis; preparative techniques and thin layer chromatography; green chemistry. The Chemical Industry (CI) – Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas. Notes
The storyline opens with a look at crop production and the nitrogen cycle, which leads into consolidation of redox concepts from the first year and introduces nitrogen chemistry. 3 hours for nitrate(V) (heat with alkali Devarda's alloy) and ammonium (heat with sodium hydroxide) ions and test for ammonia with damp pH paper – for example see . Main chemical aspects of nitrogen chemistry Facts and ethics associated with chemists' improvement of food production is no longer required. The industrial production of nitric acid, used in the fertiliser industry, forms the context for developing further understanding of equilibria and of Kc and the introduction of how to determine units. 5 hours Experiments to measure Kc – for example . Practice of identification/ calculation of initial and equilibrium concentrations in the questions before substitution into Kc – e.g. use of the . General practice of algebraic skills may also be required – for example . Evaluating the effects of changing experimental parameters on the of Kc. Main chemical ideas: equilibrium and equilibrium constant calculations; effects of factors on the equilibrium yields of reactions; consideration of the best conditions for an industrial process. Kc calculations using initial concentrations is new content. Questions involving industrial processes will include information for the learners to use – recall is not required. Kc calculations: Notes are available on websites such as .
The industrial production of sulfuric acid, used in the fertiliser industry, the context for developing understanding of rates, including determination of rate equations. 12 hours PAG9 & 10 – Rates of reaction – continuous monitoring and initial rates methods Experiments to determine the change of rate of reaction over time – for example . Experiments where the results can be used to calculate rate, orders of reaction, the rate constant and the activation enthalpy – for example . Techniques and procedures for experiments, and problem solving in reaction kinetics (HSW 4) Main chemical ideas: kinetics; effects of factors on the rate of reactions; consideration of the best conditions for an industrial process. Accurate use of the following terms will be required: rate of reactions, rate constant, order of reaction, rate equations, rate Use of the Arrhenius equation is new content. Notes can be found on websites such as and . Both versions of the Arrhenius equation are given on the . Teaching and revision of use of the ln and e functions on calculators and the straight line equation may be required. Graphical methods in kinetics is new content. Questions involving industrial processes will include information for the learners to use – recall is not required.
Finally, aspirin – discussed in WM – is revisited as the context for a more detailed discussion of mass spectrometry, as well as introduction of proton and carbon-13 NMR and the use of combined techniques in structural analysis. 7 hours Solving spectroscopic problems using a range of data (HSW 2). Solving advanced spectroscopic problems using a range of data (HSW 5). There are many examples of spectra available at . Main chemical ideas: structural analysis Carbon-13 NMR is new content. Introductory notes can be found on websites such as , , and . All carbon-13 NMR spectra that are assessed will be proton decoupled (i.e. unsplit For proton NMR, explanation of splitting patterns up to quartets using the ‘n + 1’ rule is required; further explanation of splitting is not required. Spectroscopic analysis offers opportunities for many different types of teaching, including individual and group-work, and The Oceans (O) – Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas. Notes
A study of the role of the oceans in redistributing energy from the Sun next forms the context for introducing the greenhouse effect. The absorption of CO2 by the oceans also provides the basis for introduction of acid–base equilibria, including Brønsted–Lowry theory, pH calculations, strong and weak acids, and buffers. The role of calcium carbonate in seashells as a carbon store then leads into understanding of solubility products. 11 hours PAG11 – pH measurements. Experiments involving: (i) Ka and the pH of acids and alkalis; (ii) buffer solutions; (iii) solubility products. Carry out plenty of pH and pKa calculations, and make appropriate mathematical approximations in buffer solution calculations. Using the Brønsted–Lowry theory of acids and bases to explain equilibria (HSW 1). Considering and evaluating the role of carbon dioxide and its concentration in the atmosphere on the greenhouse effect (HSW 10, 11, 12). How buffers work (including in everyday applications) (HSW 9). Main chemical ideas: the greenhouse effect, acid-base equilibria and pH, solubility product Accurate use of the following terms will be required: solubility product, conjugate acid and conjugate base, strong acid, strong base, weak acid, pH, buffer. The value of Kw is given on the . Use of quadratic equations in pH calculations will not be required. Methods of CO2 control are not required. Solubility products is new content. Notes can be found on websites such as and .
Finally, the storyline returns to the redistribution of energy by the oceans, forming the basis of an discussion of ideas relating to entropy. 4 hours Experiments to determine what drives reactions (for example ). Solving entropy problems (HSW 3). Main chemical entropy Developing Metals (DM) – Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas. Notes
The storyline continues with redox chemistry and electrochemical cells, studied in the context of cells from Volta through modern-day usage of cells to electrochemistry in the mouth. 7 hours PAG8 – Electrochemical cells. Experiments in setting up and using electrochemical cells – for example . Experiments in which electrode potentials are used to predict or interpret reactions – for example . Experiments on rusting – for example . Techniques and procedures to set up and use electrochemical cells (HSW 4). Explain rusting and its prevention (HSW 8). Main chemical cell and electrode potentials, Accurate use of the following term will be required: standard electrode potential. Balancing half equations and equations including acid-base reaction using oxidation states is new content. Notes can be found on websites such as and . Balancing equation examples: MnO4–+5e–+8H+ Mn2++4H2O MnO4–+5Fe2++8H+ Mn2++5Fe3++4H2O Details of the set-up of the hydrogen electrode are not required, just the equation for the reaction. Learners should know the standard conditions. Recycling of iron and steel is no longer required.
The storyline then moves on to synthetic dyes, including picric acid, chrysodin and mauveine. The concepts explored in this context includes electrophilic substitution reactions of benzene, and formation of diazonium compounds. At this point, the storyline also takes a look at the overall structure of dye molecules and how dyes attach themselves to fibres. 7 hours Test-tube reactions involving dye making and dyeing – for example . Dye kits are available for example . Experiments involving reactions of aromatic compounds – for example . Using scientific knowledge to modify the chromophore in relation to dyes (HSW 2). Formation of diazonium compounds (HSW 9). Main chemical ideas: aromatic compounds and their reactions, dyes and dyeing, diazonium compounds. Details of dye structures will be given. Knowledge of ionic-liquids is no longer required. The common representations of benzene to be considered are the delocalised model and the triene model. Naming of aromatic acylated products is not required.
Food dyes and food testing then form the context for studying the structure of fats and oils and the principles of gas–liquid chromatography. The storyline ends with reactions of carbonyl compounds, and case studies to illustrate the synthesis of organic molecules. 13 hours PAG7 – Qualitative analysis of organic functional groups. Test-tube reactions to identify or distinguish between unknown organic compounds with functional groups mentioned in the specification – for example . Devising and explaining organic syntheses (HSW 5, 8) Drawing and using mechanisms to explain chemical reactions (HSW 1, 8) Main chemical ideas: fats and oils, chromatography, carbonyl compounds and their reactions, organic synthesis and polyfunctional compounds. Reactions of carbonyls with Fehling's solution and Tollen's reagent are new content. can be found on websites such as and . For the reaction of carbonyl compounds, learners should be able to write the formulae of products formed, but not full equations. Further reactions that learners are expected to consider are given on the . Chemical Literacy (CL) Specification reference & statements Suggested teaching time Delivery Guides Suggested practicals, PAGs. HSW and maths skills ideas. Notes Throughout the course, learners will be given (throughout the course) Use of previous series’ Advanced Notice articles – for example and . Chemical literacy will be formally assessed across the three written components in the A Level assessment.
ES – Section 1 – (b), (c), (d), (e), (f), (g), (h), (i), (j), (k) The presence of halide in the sea provides the entry to the properties of the halogens and reactions between halide ions. The manufacture of bromine and chlorine then provide the context for discussion of redox chemistry, electrolysis and the nomenclature of inorganic compounds. (b) the explanation (given the necessary information) of the chemical processes occurring during the extraction of the halogens from minerals in the sea (c) techniques and procedures in the electrolysis of aqueous solutions; half-equations for the processes occurring at electrodes in electrolysis of molten salts and aqueous solutions: (i) formation of oxygen or a halogen or metal ions at the anode; (ii) formation of hydrogen or a metal at the cathode (d) reactions of s-, p- and d-block elements and their compounds in terms of electron transfer: (i) use of half-equations to represent simple oxidation and reduction reactions; (ii) the definition of oxidation and reduction as loss and gain of electrons; (iii) identification of oxidising and reducing agents (e) the oxidation states assigned to and calculated for specified atoms in formulae (including ions) and explanation of which species have been oxidised and which reduced in a redox reaction (f) use of oxidation states to balance redox equations that do not also involve acid–base reactions; ….. (g) use of systematic nomenclature to name and interpret the of inorganic compounds (h) a description of the following physical properties of the halogens: appearance and physical state at room temperature, volatility, solubility in water and organic solvents (i) the relative reactivities of the halogens in terms of their ability to gain electrons (j) the details of the redox changes which take place when chlorine, bromine and iodine react with other halide ions, including observations, equations and half-equations (k) the reactions between halide ions (Cl–, Br– and I–) and silver ions (Ag+) and ionic equations to represent these precipitation reactions, the colours of the precipitates and the solubility of silver halides in ammonia
CD – Section 3 – (c), (f), (i), (j), (k), (l), (n) Food dyes and food testing then form the context for studying the structure of fats and oils and the principles of gas–liquid chromatography. The storyline ends with reactions of carbonyl compounds, and case studies to illustrate the synthesis of organic molecules. (c) fats and oils consist mainly of esters of propane-1,2,3-triol with varying degrees of unsaturation (f) naming the individual functional groups mentioned elsewhere in the specification within a polyfunctional molecule and making predictions about the properties of the polyfunctional molecule; testing for these functional groups in a compound, using reactions mentioned in the specification (i) the following reactions involving carbonyl compounds (aldehydes and ketones): (i) oxidation of aldehydes to carboxylic acids using acidified dichromate, under reflux; (ii) reaction with Fehling’s solution and Tollens' reagent; (iii) reaction with cyanide ions to form the cyanohydrin (j) use of organic reactions and reaction conditions mentioned here and elsewhere in the specification to suggest and explain synthetic routes for preparing organic compounds (k) the mechanism of the nucleophilic addition reaction between a carbonyl compound and CN–, using ‘curly arrows’ and partial charges (l) organic mechanisms: (i) use of the following terms to classify organic reactions: addition, condensation, elimination, substitution, oxidation, reduction, hydrolysis; (ii) use of ‘curly arrows’ and partial charges, where appropriate, to describe unfamiliar mechanisms, given appropriate information (n) the general principles of gas–liquid chromatography: (i) sample injected into inert carrier gas stream; (ii) column consisting of high boiling liquid on porous support; (iii) detection of the emerging compounds (sometimes involving mass spectrometry); (iv) distinguishing compounds by their retention times.