A Level Chemistry Syllabus

CHEMISTRY HIGHER 2 (Syllabus 9647) CONTENTS Page INTRODUCTION 1 AIMS 1 ASSESSMENT OBJECTIVES 2 SCHEME OF ASSESSMENT 4 ADDITIONAL INFORMATION 6 SUBJECT CONTENT 7 PRACTICAL ASSESSMENT 27 QUALITATIVE ANALYSIS NOTES 29 SUMMARY OF KEY QUANTITIES AND UNITS 31 MATHEMATICAL REQUIREMENTS 32 GLOSSARY OF TERMS 33 DATA BOOKLET 36 PERIODIC TABLE 46 TEXTBOOKS 47 9647 H2 CHEMISTRY (2013) 1 INTRODUCTION Candidates will be assumed to have knowledge and understanding of Chemistry at O level, as a single subject or as part of a balanced science course. This syllabus is designed to place less emphasis on factual material and greater emphasis on the understanding and application of scientific concepts and principles. This approach has been adopted in recognition of the need for students to develop skills that will be of long term value in an increasingly technological world rather than focusing on large quantities of factual material which may have only short term relevance. Experimental work is an important component and should underpin the teaching and learning of Chemistry. AIMS These are not listed in order of priority. Many of these Aims are reflected in the Assessment Objectives which follow; others are not readily assessed. The aims are to 1. provide, through well designed studies of experimental and practical chemistry, a worthwhile educational experience for all students, whether or not they go on to study science beyond this level and, in particular, to enable them to acquire sufficient understanding and knowledge to 1.1 become confident citizens in a technological world, able to take or develop an informed interest in matters of scientific import; 1.2 recognise the usefulness, and limitations, of scientific method and to appreciate its applicability in other disciplines and in everyday life; 1.3 be suitably prepared for employment and/or further studies beyond A level. 2. develop abilities and skills that 2.1 are relevant to the study and practice of science; 2.2 are useful in everyday life; 2.3 encourage efficient and safe practice; 2.4 encourage the presentation of information and ideas appropriate for different audiences and purposes; 2.5 develop self motivation and the ability to work in a sustained fashion. 9647 H2 CHEMISTRY (2013) 2 3. develop attitudes relevant to science such as 3.1 accuracy and precision; 3.2 objectivity; 3.3 integrity; 3.4 enquiry; 3.5 initiative; 3.6 insight. 4. stimulate interest in, and care for, the environment. 5. promote an awareness that 5.1 the study and practice of science are co-operative and cumulative activities, and are subject to social, economic, technological, ethical and cultural influences and limitations; 5.2 the applications of science may be both beneficial and detrimental to the individual, the community and the environment; 5.3 science transcends national boundaries and that the language of science, correctly and rigorously applied, is universal; 5.4 the use of information technology is important for communication, as an aid to experiments and as a tool for interpretation of experimental and theoretical results. ASSESSMENT OBJECTIVES The assessment objectives listed below reflect those parts of the Aims which will be assessed. A Knowledge with understanding Students should be able to demonstrate knowledge with understanding in relation to: 1. scientific phenomena, facts, laws, definitions, concepts, theories; 2. scientific vocabulary, terminology, conventions (including symbols, quantities and units); 3. scientific instruments and apparatus, including techniques of operation and aspects of safety; 4. scientific quantities and their determination; 5. scientific and technological applications with their social, economic and environmental implications. The Syllabus Content defines the factual knowledge that candidates may be required to recall and explain. Questions testing these objectives will often begin with one of the following words: define, state, describe, explain or outline. (See the Glossary of Terms.) 9647 H2 CHEMISTRY (2013) 3 B Handling, applying and evaluating information Students should be able in words or by using symbolic, graphical and numerical forms of presentation to: 1. locate, select, organise and present information from a variety of sources; 2. handle information, distinguishing the relevant from the extraneous; 3. manipulate numerical and other data and translate information from one form to another; 4. analyse and evaluate information so as to identify patterns, report trends and conclusions, and draw inferences; 5. present reasoned explanations for phenomena, patterns and relationships; 6. construct arguments to support hypotheses or to justify a course of action; 7. apply knowledge, including principles, to novel situations; 8. evaluate information and hypotheses; 9. demonstrate an awareness of the limitations of Chemistry theories and models; 10. bring together knowledge, principles and concepts from different areas of chemistry, and apply them in a particular context; 11. use chemical skills in contexts which bring together different areas of the subject. These assessment objectives cannot be precisely specified in the Syllabus Content because questions testing such skills may be based on information which is unfamiliar to the candidate. In answering such questions, candidates are required to use principles and concepts that are within the syllabus and apply them in a logical, reasoned or deductive manner to a novel situation. Questions testing these objectives will often begin with one of the following words: predict, suggest, construct, calculate or determine. (See the Glossary of Terms.) C Experimental skills and investigations Students should be able to: 1. devise and plan investigations, select techniques, apparatus and materials; 2. use techniques, apparatus and materials safely and effectively; 3. make and record observations, measurements and estimates; 4. interpret and evaluate observations and experimental data; 5. evaluate methods and suggest possible improvements. 9647 H2 CHEMISTRY (2013) 4 SCHEME OF ASSESSMENT All school candidates are required to enter for Papers 1, 2, 3 and 4. All private candidates are required to enter for Papers 1, 2, 3 and 5. Paper Type of Paper Duration Weighting (%) Marks 1 Multiple Choice 1 h 20.0 40 2 Structured Questions Planning 2 h 25.0 5.0 60 12 3 Free Response Questions 2 h 35.0 80 4 School-based Science Practical Assessment (SPA) - 15.0 40 5 Practical Paper 1 h 50 min 15.0 36 Paper 1 (1 h)(40 marks) Forty multiple choice questions, all compulsory. Thirty items will be of the direct choice type and ten of the multiple completion type. All questions will include 4 responses. Paper 2 (2 h)(72 marks) A variable number of structured questions including one or two data-based questions and a question on Planning. All questions are compulsory and answered on the question paper. The data-based question(s) constitute(s) 15–20 marks for this paper whilst the Planning question constitutes 12 marks for this paper. The data-based question(s) provide(s) good opportunity to test higher order thinking skills such as handling, applying, and evaluating information. The Planning Question will assess appropriate aspects of objectives C1 to C5. Some questions, including the Planning question, will also require candidates to integrate knowledge and understanding from different areas and topics of the chemistry syllabus. Paper 3 (2 h)(80 marks) Candidates will be required to answer a total of four out of five questions. Each question will carry 20 marks. All the questions will require candidates to integrate knowledge and understanding from different areas and topics of the chemistry syllabus. Paper 4 (40 marks) The School-Based Science Practical Assessment (SPA) will take place over an appropriate period that the candidates are offering the subject. There are two compulsory assessments which will assess appropriate aspects of objectives C1 to C5 in the following skill areas: • Manipulation, measurement and observation (MMO) • Presentation of data and observations (PDO) • Analysis, conclusions and evaluation (ACE) 9647 H2 CHEMISTRY (2013) 5 Each assessment assesses these three skill areas MMO, PDO and ACE, which may not be necessarily equally weighted, to a total of 20 marks. The range of marks for the three skill areas are as follows: MMO, 4–8 marks; PDO, 4–8; ACE, 8–10 marks. The assessment of PDO and ACE may also include questions on data-analysis which do not require practical equipment and apparatus. Candidates will not be permitted to refer to books and laboratory notebooks during the assessment. Refer to the SPA Handbook for more detailed information on the conduct of SPA. Paper 5 (1 h 50 min, 36 marks) For private candidates, a timetabled practical paper will assess appropriate aspects of objectives C1 to C5 in the following skill areas: • Manipulation, measurement and observation (MMO) • Presentation of data and observations (PDO) • Analysis, conclusions and evaluation (ACE) Each of these skill areas will be approximately equally weighted to a total of 36 marks. This paper may include data handling/interpretation questions that do not require apparatus, in order to test the skill areas of PDO and ACE. Candidates will not be permitted to refer to books and laboratory notebooks during the examination. Marks allocated to assessment objectives and syllabus areas Assessment Objectives Weighting Assessment Components A Knowledge with understanding 32% Papers 1, 2, 3 B Handling, applying and evaluating information 48% Papers 1, 2, 3 C Experimental skills and investigations 20% Papers 2, 4 or Papers 2, 5 The proportion of marks allocated to Physical, Inorganic and Organic Chemistry in Papers 1, 2 and 3 will be in the approximate ratio 5:2:5. 9647 H2 CHEMISTRY (2013) 6 ADDITIONAL INFORMATION Data Booklet A Data Booklet is available for use in the theory papers. The booklet is reprinted at the end of this syllabus document. Nomenclature Students will be expected to be familiar with the nomenclature used in the syllabus. The proposals in "Signs, Symbols and Systematics" (The Association for Science Education Companion to 16-19 Science, 2000) will generally be adopted although the traditional names sulfate, sulfite, nitrate, nitrite, sulfurous and nitrous acids will be used in question papers. Sulfur (and all compounds of sulfur) will be spelt with f (not with ph) in question papers, however students can use either spelling in their answers. Grading Conditions Candidates’ results are based on the aggregation of their marks in the various papers, i.e. there are no hurdle conditions under which a prescribed level of performance in an individual paper prevents the award of an A level result. Disallowed Subject Combinations Candidates may not simultaneously offer Chemistry at H1 and H2. 9647 H2 CHEMISTRY (2013) 7 SUBJECT CONTENT PHYSICAL CHEMISTRY 1. ATOMS, MOLECULES AND STOICHIOMETRY Content • Relative masses of atoms and molecules • The mole, the Avogadro constant • The calculation of empirical and molecular formulae • Reacting masses and volumes (of solutions and gases) Learning Outcomes [the term relative formula mass or Mr will be used for ionic compounds] Candidates should be able to: (a) define the terms relative atomic, isotopic, molecular and formula mass, based on the 12 C scale (b) define the term mole in terms of the Avogadro constant (c) calculate the relative atomic mass of an element given the relative abundances of its isotopes (d) define the terms empirical and molecular formula (e) calculate empirical and molecular formulae using combustion data or composition by mass (f) write and/or construct balanced equations (g) perform calculations, including use of the mole concept, involving: (i) reacting masses (from formulae and equations) (ii) volumes of gases (e.g. in the burning of hydrocarbons) (iii) volumes and concentrations of solutions [when performing calculations, candidates’ answers should reflect the number of significant figures given or asked for in the question] (h) deduce stoichiometric relationships from calculations such as those in (g) 2. ATOMIC STRUCTURE Content • The nucleus of the atom: neutrons and protons, isotopes, proton and nucleon numbers • Electrons: electronic energy levels, ionisation energies, atomic orbitals, extranuclear structure Learning Outcomes Candidates should be able to: (a) identify and describe protons, neutrons and electrons in terms of their relative charges and relative masses 9647 H2 CHEMISTRY (2013) 8 (b) deduce the behaviour of beams of protons, neutrons and electrons in an electric field (c) describe the distribution of mass and charges within an atom (d) deduce the numbers of protons, neutrons and electrons present in both atoms and ions given proton and nucleon numbers (and charge) (e) (i) describe the contribution of protons and neutrons to atomic nuclei in terms of proton number and nucleon number (ii) distinguish between isotopes on the basis of different numbers of neutrons present (f) describe the number and relative energies of the s, p and d orbitals for the principal quantum numbers 1, 2 and 3 and also the 4s and 4p orbitals (g) describe the shapes of s and p orbitals (h) state the electronic configuration of atoms and ions given the proton number (and charge) (i) (i) explain the factors influencing the ionisation energies of elements (see the Data Booklet) (ii) explain the trends in ionisation energies across a period and down a Group of the Periodic Table (see also Section 9) (j) deduce the electronic configurations of elements from successive ionisation energy data (k) interpret successive ionisation energy data of an element in terms of the position of that element within the Periodic Table 3. CHEMICAL BONDING Content • Ionic (electrovalent) bonding • Covalent bonding and co-ordinate (dative covalent) bonding (i) The shapes of simple molecules (ii) Bond energies, bond lengths and bond polarities • Intermolecular forces, including hydrogen bonding • Metallic bonding • Bonding and physical properties • The solid state Learning Outcomes Candidates should be able to: (a) describe ionic (electrovalent) bonding, as in sodium chloride and magnesium oxide, including the use of ‘dot-and-cross’ diagrams (b) describe, including the use of ‘dot-and-cross’ diagrams, (i) covalent bonding, as in hydrogen; oxygen; nitrogen; chlorine; hydrogen chloride; carbon dioxide; methane; ethene (ii) co-ordinate (dative covalent) bonding, as in formation of the ammonium ion and in the Al2Cl6 molecule. 9647 H2 CHEMISTRY (2013) 9 (c) explain the shapes of, and bond angles in, molecules such as BF3 (trigonal planar); CO2 (linear); CH4 (tetrahedral); NH3 (trigonal pyramidal); H2O (non-linear); SF6 (octahedral) by using the Valence Shell Electron Pair Repulsion theory (d) describe covalent bonding in terms of orbital overlap, giving σ and π bonds (see also Section 10.1) (e) predict the shapes of, and bond angles in, molecules analogous to those specified in (c) (f) describe hydrogen bonding, using ammonia and water as examples of molecules containing -NH and -OH groups (g) explain the terms bond energy, bond length and bond polarity and use them to compare the reactivities of covalent bonds (h) describe intermolecular forces (van der Waals’ forces), based on permanent and induced dipoles, as in CHCl3(l); Br2(l) and the liquid noble gases (i) describe metallic bonding in terms of a lattice of positive ions surrounded by mobile electrons (j) describe, interpret and/or predict the effect of different types of bonding (ionic bonding; covalent bonding; hydrogen bonding; other intermolecular interactions; metallic bonding) on the physical properties of substances (k) deduce the type of bonding present from given information (l) show understanding of chemical reactions in terms of energy transfers associated with the breaking and making of chemical bonds (m) describe, in simple terms, the lattice structure of a crystalline solid which is: (i) ionic, as in sodium chloride, magnesium oxide (ii) simple molecular, as in iodine (iii) giant molecular, as in graphite; diamond (iv) hydrogen-bonded, as in ice (v) metallic, as in copper [the concept of the ‘unit cell’ is not required] (n) outline the importance of hydrogen bonding to the physical properties of substances, including ice and water (o) suggest from quoted physical data the type of structure and bonding present in a substance (p) recognise that materials are a finite resource and the importance of recycling processes 4. THE GASEOUS STATE Content • Ideal gas behaviour and deviations from it • pV = nRT and its use in determining a value for Mr 9647 H2 CHEMISTRY (2013) 10 Learning Outcomes Candidates should be able to: (a) state the basic assumptions of the kinetic theory as applied to an ideal gas (b) explain qualitatively in terms of intermolecular forces and molecular size: (i) the conditions necessary for a gas to approach ideal behaviour (ii) the limitations of ideality at very high pressures and very low temperatures (c) state and use the general gas equation pV = nRT in calculations, including the determination of Mr 5. CHEMICAL ENERGETICS Content • Enthalpy changes: ∆H, of formation; combustion; hydration; solution; neutralisation; atomisation; bond energy; lattice energy; electron affinity • Hess’ Law, including Born-Haber cycles • Entropy and Free Energy Learning Outcomes Candidates should be able to: (a) explain that some chemical reactions are accompanied by energy changes, principally in the form of heat energy; the energy changes can be exothermic (∆H negative) or endothermic (∆H positive) (b) explain and use the terms: (i) enthalpy change of reaction and standard conditions, with particular reference to: formation; combustion; hydration; solution; neutralisation; atomisation (ii) bond energy (∆H positive, i.e. bond breaking) (iii) lattice energy (∆H negative, i.e. gaseous ions to solid lattice) (c) calculate enthalpy changes from appropriate experimental results, including the use of the relationship heat change = mc∆T (d) explain, in qualitative terms, the effect of ionic charge and of ionic radius on the numerical magnitude of a lattice energy (e) apply Hess’ Law to construct simple energy cycles, e.g. Born-Haber cycle, and carry out calculations involving such cycles and relevant energy terms (including ionisation energy and electron affinity), with particular reference to: (i) determining enthalpy changes that cannot be found by direct experiment, e.g. an enthalpy change of formation from enthalpy changes of combustion (ii) the formation of a simple ionic solid and of its aqueous solution (iii) average bond energies 9647 H2 CHEMISTRY (2013) 11 (f) construct and interpret a reaction pathway diagram, in terms of the enthalpy change of the reaction and of the activation energy (g) explain and use the term entropy (h) discuss the effects on the entropy