In this lesson we discuss the liquid state, phase changes and the concept of vapour pressure. This is lesson thirteen in our physical chemistry series for Unit 4: States of Matter (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Understand the liquid state using the kinetic model and describe how particles behave during phase changes and at vapour pressure. Learning Outcomes (from the Cambridge AS Chemistry Curriculum 2019-2021): 4.2 The liquid state a) describe, using a kinetic-molecular model, the liquid state, melting, vaporisation and vapour pressure.

In this lesson we discuss the concept of Hess’ Law based on the first law of thermodynamics and how this can be used to create enthalpy cycles to determine unknown enthalpy changes. This is lesson seventeen in our physical chemistry series for Unit 5: Chemical Energetics (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Understand and apply Hess’ law through enthalpy cycles. Calculate enthalpy changes through bond energies and vice versa. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 5.2 Hess’ Law, including Born-Haber cycles a) apply Hess’ Law to construct simple energy cycles, and carry out calculations involving such cycles and relevant energy terms, 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) average bond energies b) construct and interpret a reaction pathway diagram, in terms of the enthalpy change of the reaction and of the activation energy

In this lesson we discuss the concept of reversible reactions, dynamic equilibrium, Le Chatelier’s principle and how Le Chatelier’s principle is linked to temperature, concentration and pressure. This is lesson twenty in our physical chemistry series for Unit 7: Equilibria (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Understand the concepts of a reversible reaction and dynamic equilibrium and how they apply to Le Chatelier’s principle in different contexts. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 7.1 Chemical equilibria: reversible reactions, dynamic equilibrium a) explain, in terms of rates of the forward and reverse reactions, what is meant by a reversible reaction and dynamic equilibrium b) state Le Chatelier’s principle and apply it to deduce qualitatively (from appropriate information) the effects of changes in temperature, concentration or pressure on a system at equilibrium c) state whether changes in temperature, concentration or pressure or the presence of a catalyst affect the value of the equilibrium constant for a reaction.

In this lesson we discuss the concept of using oxidation states to determine whether a species has been reduced or oxidised, introduce the idea of oxidising and reducing agents, how to use oxidation for naming conventions and how to use oxidation numbers to balance redox reactions. This is lesson nineteen in our physical chemistry series for Unit 6: Electrochemistry (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Use oxidation numbers to determine oxidising and reducing agents, understand naming conventions and to balance chemical equations. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state) c) use changes in oxidation numbers to help balance chemical equations

In this lesson we discuss the concept of redox processes from reduction and oxidation reactions, half equations, ionic equations and how to determine oxidation states (oxidation numbers). This is lesson eighteen in our physical chemistry series for Unit 6: Electrochemistry (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Understand and explain redox reactions in terms of electron transfer and oxidation numbers. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 6.1 Redox processes: electron transfer and changes in oxidation number (oxidation state) a) calculate oxidation numbers of elements in compounds and ions b) describe and explain redox processes in terms of electron transfer and changes in oxidation number

LESSON OBJECTIVE: Describe reactions of period 3 elements with oxygen and water and investigate the periodicity of Period 3 oxides. In this lesson we link the concept of periodicity to chemical properties by investigating the formation and reactions of Period 3 oxides. This is lesson two in our inorganic chemistry series for Unit 9: The Periodic Table: chemical periodicity (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 9.2 Periodicity of chemical properties of the elements in Period 3 a) describe the reactions, if any, of the elements with oxygen (to give Na2O, MgO, Al2O3, P4O10, SO2, SO3), chlorine (to give NaCl, MgCl2, Al2Cl6, SiCl4, PCl5) and water (Na and Mg only) b) state and explain the variation in oxidation number of the oxides (sodium to sulfur only) and chlorides (sodium to phosphorus only) in terms of their outer shell (valence shell) electrons c) describe the reactions of the oxides with water (treatment of peroxides and superoxides is not required) d) describe and explain the acid/base behaviour of oxides and hydroxides including, where relevant, amphoteric behaviour in reactions with acids and bases (sodium hydroxide only) f) interpret the variations and trends in 9.2(b), ©, (d) and (e) in terms of bonding and electronegativity g) suggest the types of chemical bonding present in chlorides and oxides from observations of their chemical and physical properties 9.1 Periodicity of physical properties of the elements in Period 3 e) explain the strength, high melting point and electrical insulating properties of ceramics in terms of their giant structure; to include magnesium oxide, aluminium oxide and silicon dioxide

LESSON OBJECTIVE: Understand the periodicity of the Period 3 chlorides and for other elements in the Periodic Table In this lesson we investigate the periodicity observed in the Period 3 chlorides and extrapolate our understanding of periodicity to other elements beyond just Period 3 in the Periodic Table. This is lesson three in our inorganic chemistry series for Unit 9: The Periodic Table: chemical periodicity (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 9.2 Periodicity of chemical properties of the elements in Period 3 a) describe the reactions, if any, of the elements with oxygen (to give Na2O, MgO, Al2O3, P4O10, SO2, SO3), chlorine (to give NaCl, MgCl2, Al2Cl6, SiCl4, PCl5) and water (Na and Mg only) b) state and explain the variation in oxidation number of the oxides (sodium to sulfur only) and chlorides (sodium to phosphorus only) in terms of their outer shell (valence shell) electrons e) describe and explain the reactions of the chlorides with water f) interpret the variations and trends in 9.2(b), ©, (d) and (e) in terms of bonding and electronegativity g) suggest the types of chemical bonding present in chlorides and oxides from observations of their chemical and physical properties 9.3 Chemical periodicity of other elements a) predict the characteristic properties of an element in a given group by using knowledge of chemical periodicity b) deduce the nature, possible position in the Periodic Table and identify of unknown elements from given information about physical and chemical properties

In this lesson we discuss calculations with equilibrium constants using the ‘RICE table’ method and how equilibria can effect industrial chemical production, specifically in the Haber process and the Contact process. This is lesson twenty two in our physical chemistry series for Unit 7: Equilibria (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Apply the concepts of equilibria and equilibrium constants to laboratory procedures, including industrially with the Haber and Contact processes. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 7.1 Chemical equilibria: reversible reactions, dynamic equilibrium f) calculate the quantities present at equilibrium, given appropriate data (such calculations will not require the solving of quadratic equations) g) describe and explain the conditions used in the Haber process and the Contact process, as examples of the importance of an understanding of chemical equilibrium in the chemical industry

LESSON OBJECTIVE: Explain the trends observed across the periodic table including atomic radius, ionic radius, melting point, electrical conductivity and first ionisation energy. In this lesson we discuss the concept of periodicity and justify the trends we observe in a number of physical properties as we move across the Period 3 elements. This is lesson one in our inorganic chemistry series for Unit 9: The Periodic Table: chemical periodicity (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 9.1 Periodicity of physical properties of the elements in Period 3 a) describe qualitatively (and indicate the periodicity in) the variations in atomic radius, ionic radius, melting point and electrical conductivity of the elements (see the Data Booklet) b) explain qualitatively the variation in atomic radius and ionic radius c) interpret the variation in melting point and electrical conductivity in terms of the presence of simple molecular, giant molecular or metallic bonding in the elements d) explain the variation in first ionisation energy (see the Data Booklet)

In this lesson we discuss equilibrium constants and how to determine them using concentrations and partial pressures, and discuss how certain factors can change the value of an equilibrium constant. This is lesson twenty one in our physical chemistry series for Unit 7: Equilibria (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Understand and calculate equilibrium constants (Kc and Kp), determine their units and interpret how certain factors can affect its value. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): c) state whether changes in temperature, concentration or pressure or the presence of a catalyst affect the value of the equilibrium constant for a reaction. d) deduce expressions for equilibrium constants in terms of concentrations, Kc , and partial pressures, Kp (treatment of the relationship between Kp and Kc is not required) e) calculate the values of equilibrium constants in terms of concentrations or partial pressures from appropriate data

LESSON OBJECTIVE: Understand and describe the trends in the physical and chemical properties of the Group 2 Metals. In this lesson we investigate the trends observed in the Group 2 metals physical properties, including atomic radius, melting point and density, and begin to discuss the properties in their chemical properties. This is lesson four in our inorganic chemistry series for Unit 10: Group 2 (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 10.1 Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds a) describe the reactions of the elements with oxygen, water and dilute acids b) describe the behaviour of the oxides, hydroxides and carbonates with water and dilute acids d) interpret, and make predictions from, the trends in physical and chemical properties of the elements and their compounds

In this lesson we introduce the concept of reaction kinetics focusing on collision theory, rates of reaction, activation energy and the effect that changing concentration and pressure will have on reaction rates. This is lesson twenty four in our physical chemistry series for Unit 8: Reaction kinetics (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Define rate of reactions in terms of collision theory and activation energy and understand the effect concentration has on reaction rates. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 8.1 Simple Rate Equations, Orders of Reaction and Rate Constants a) explain and use the term rate of reaction b) explain qualitatively, in terms of collisions, the effect of concentration changes on the rate of reaction

In this lesson we describe the relationship between temperature and reaction rates and introduce the concept of the Boltzmann distribution. This is lesson twenty five in our physical chemistry series for Unit 8: Reaction kinetics (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Describe the effect of temperature on reaction rates and illustrate this on a Boltzmann distribution. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 8.2 Effect of temperature: on reaction rates and rate constants and the concept of activation energy a) explain and use the term activation energy, including reference to the Boltzmann distribution b) explain qualitatively, in terms both of the Boltzmann distribution and of collision frequency, the effect of temperature change on the rate of a reaction

LESSON OBJECTIVE: Identify characteristic organic functional groups and understand the naming and drawing conventions for organic molecules. In this lesson we introduce the discipline of organic chemistry, in particular introducing different formulas to represent organic molecules, key functional groups and the rules concerning organic nomenclature. This is lesson one in our organic chemistry series for Unit 14 An introduction to organic chemistry (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 14.1 Formulae, functional groups and the naming of organic compounds a) interpret and use the general, structural, displayed and skeletal formulae of the following classes of compound: (i) alkanes, alkenes (ii) halogenoalkanes (iii) alcohols (including primary, secondary and tertiary) (iv) aldehydes and ketones (v) carboxylic acids, esters (vi) amines (primary only), nitriles b) understand and use systematic nomenclature of simple aliphatic organic molecules with functional groups detailed in 14.1 (a), up to six carbon atoms (six plus six for esters and amides, straight chains only) d) deduce the possible isomers for an organic molecule of known molecular formula e) deduce the molecular formula of a compound, given its structural, displayed or skeletal formula

LESSON OBJECTIVE: Use orbital hybridisation to determine the shape of an organic molecule and understand and identify different types of structural isomerism and stereoisomerism. In this lesson we discuss how hybridisation, molecular geometries and sigma and pi bonds are linked to organic structure and formulas. We then introduce isomerism by looking at the different types of structural isomerism (position, functional group and chain) and stereoisomerism (cis-trans and optical). This is lesson two in our organic chemistry unit for Unit 14: An introduction to organic chemistry (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 14.3 Shapes of organic molecules; σ and π bonds a) (i) describe and explain the shape of, and bond angles in, the ethane and ethene molecules a) in terms of σ and π bonds (ii) predict the shapes of, and bond angles in, other related molecules 14.4 Isomerism: structural and stereoisomerism a) describe structural isomerism and its division into chain, positional and functional group isomerism b) describe stereoisomerism and its division into geometrical (cis-trans) and optical isomerism (use of E, Z nomenclature is acceptable but is not required) c) describe geometrical (cis-trans) isomerism in alkenes, and explain its origin in terms of restricted rotation due to the presence of π bonds d) explain what is meant by a chiral centre and that such a centre normally gives rise to optical isomerism e) identify chiral centres and geometrical (cis-trans) isomerism in a molecule of given structural formula

LESSON OBJECTIVE: Understand the properties and uses of nitrogen and ammonia. In this lesson we investigate Nitrogen, the formation of its oxides, the Haber process to synthesise ammonia and the use of ammonium salts as fertilizers. This is lesson eight in our inorganic chemistry series for Unit 13: Nitrogen and sulfur (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 13.1 Nitrogen a) explain the lack of reactivity of nitrogen b) describe and explain: ii) the basicity of ammonia iii) the structure of the ammonium ion and its formation by an acid-base reaction iii) the displacement of ammonia from its salts c) state the industrial importance of ammonia and nitrogen compounds derived from ammonia d) state and explain the environmental consequences of the uncontrolled use of nitrate fertilisers e) state and explain the natural and man-made occurrences of oxides of nitrogen and their catalytic removal from the exhaust gases of internal combustion engines f) explain why atmospheric oxides of nitrogen are pollutants, including their catalytic role in the oxidation of atmospheric sulfur dioxide

LESSON OBJECTIVE: Describe certain reactions of halides and halogens and state some uses of halogens and their compounds. In this lesson we some reactions of the Halogens, the concept of disproportionation and discuss some of the uses of the halogens and their compounds. This is lesson seven in our inorganic chemistry series for Unit 11: Group 17 (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 11.3 Some reactions of the halide ions a) describe and explain the reactions of halide ions with: i) aqueous silver ions followed by aqueous ammonia ii) concentrated sulfuric acid 11.4 The reactions of chlorine with aqueous sodium hydroxide a) describe and interpret, in terms of changes of oxidation number, the reaction of chlorine with cold and with hot aqueous sodium hydroxide and recognise this as a disproportionation reaction 11.5 Some important uses of the halogens and of halogen compounds a) explain the use of chlorine in water purification b) state the industrial importance and environmental significance of the halogens and their compounds (e.g. for bleaches, PVC, halogenated hydrocarbons as solvents, refrigerants and in aerosols. See also Section 16.2).

LESSON OBJECTIVE: Describe and understand the trends observed in the physical and chemical properties of the group 17 halogens. In this lesson we investigate the physical properties and chemical reactivity of the Group 17 Halogens and investigate the formation and properties of hydrogen halides. This is lesson six in our inorganic chemistry series for Unit 11: Group 17 (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 11.1 Physical properties of the Group 17 elements a) describe the colours and the trend in volatility of chlorine, bromine and iodine b) interpret the volatility of the elements in terms of van der Waals’ forces 11.2 The chemical properties of the elements and the hydrides a) describe the relative reactivity of the elements as oxidising agents (see also Section 6.3(f)) b) describe and explain the reactions of the elements with hydrogen c) i) describe and explain the relative thermal stabilities of the hydrides ii) interpret these relative stabilities in terms of bond energies

LESSON OBJECTIVE: Understand the trends in chemical properties and some of the uses of Group 2 compounds. In this lesson we investigate chemical reactions of the Group 2 elements and their compounds and look at some uses of Group 2 compounds. This is lesson five in our inorganic chemistry series for Unit 10: Group 2 (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 10.1 Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds a) describe the reactions of the elements with oxygen, water and dilute acids b) describe the behaviour of the oxides, hydroxides and carbonates with water and dilute acids c) describe the thermal decomposition of the nitrates and carbonates e) state the variation in the solubilities of the hydroxides and sulfates 10.2 Some uses of Group 2 compounds a) describe and explain the use of calcium hydroxide and calcium carbonate (powdered limestone) in agriculture

LESSON OBJECTIVE: Describe and understand the properties of alkanes and characteristic reactions including combustion reactions and free-radical substitution reactions with chlorine and bromine. In this lesson we introduce the topic of hydrocarbons and in particular focus on the properties and reactions of the alkanes homologous series. This is lesson four in our organic chemistry series of Unit 15: Hydrocarbons (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Learning Outcomes: (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 15.1 Alkanes a) understand the general unreactivity of alkanes, including towards polar reagents b) describe the chemistry of alkanes as exemplified by the following reactions of ethane: (i) combustion (ii) substitution by chlorine and bromine c) describe the mechanism of free-radical substitution at methyl groups with particular reference to the initiation, propagation and termination reactions