In this lesson we discuss how intermolecular forces arise due to the concept of electronegativity and bond polarity and other bond properties. This is lesson ten in our physical chemistry series for Unit 3: Chemical Bonding (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/CsH7LDX77fo LESSON OBJECTIVE: Understand the different intermolecular forces and their implications for a molecules physical properties. Explain these forces in terms of electronegativity and polarity. Learning Outcomes (from the Cambridge AS Chemistry Curriculum 2019-2021): 3.3 Intermolecular forces, electronegativity and bond properties. a) describe hydrogen bonding, using ammonia and water as simple examples of molecules containing N-H and O-H groups b) understand, in simple terms, the concept of electronegativity and apply it to explain the properties of molecules such as bond polarity, the dipole moments of molecules and the behaviour of oxides with water c) explain in terms of bond energy, bond length and bond polarity and use them to compare the reactivities of covalent bonds d) describe intermolecular forces (van der Waals’ forces) based on permanent and induced dipoles, as in, for example, CHCl3(l); Br2(l) and the liquid Group 18 element.

In this lesson we focus on the concept of ionisation energy and how to interpret ionisation energy trends in the periodic table. This is lesson seven in our physical chemistry series for Unit 2: Atomic Structure (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/scvd4cSDk8c LESSON OBJECTIVE: Understand ionisation energy and use this to rationalise trends in the Periodic Table and to deduce electronic configurations of elements. To Interpret ionisation energy data. Learning Outcomes (from the Cambridge AS Chemistry Curriculum 2019-2021): 2.3 Electrons: energy levels, atomic orbitals, ionisation energy, electron affinity d) i) explain and use the term ionisation energy ii) explain the factors influencing the ionisation energies of elements iii) explain the trends in ionisation energies across a period and down a group of the Periodic Table e) deduce the electronic configurations of elements from successive ionisation energy data f) interpret successive ionisation energy data of an element in terms of the position of that element within the Periodic Table

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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/-usSO03fAOU 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

This lesson goes over the concept of stoichiometry and how to do stoichiometric calculations that involve the reactions of masses and volumes. This is lesson three in our physical chemistry series for Unit 1: Atoms, Molecules and Stoichiometry (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://www.youtube.com/watch?v=zTdfH2x-8-c LESSON OBJECTIVE: To balance equations and perform calculations using the mole concept and stoichiometric relationships. Understand the concept of a titration. LEARNING OUTCOMES (from the Cambridge AS Chemistry Curriculum 2019-2021): 1.5 Reacting masses and volumes (of solutions and gases) a) write and construct balanced equations b) 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 c) deduce stoichiometric relationships from calculations

In this lesson we discuss the formation of sigma and pi bonds, the hybridisation of orbitals and the molecular geometries that form due to electron repulsion. This is lesson nine in our physical chemistry series for Unit 3: Chemical Bonding (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/helUjpjjLTQ LESSON OBJECTIVE: Understand how sigma and pi bonds form and investigate the concept of atomic orbital hybridisation. Identify molecular geometries and understand bond angles observed due to electron pair repulsion. Learning Outcomes: (from the Cambridge AS Chemistry Curriculum 2019-2021): 3.2 Covalent bonding and co-ordinate (dative covalent) bonding including shapes of simple molecules b) describe covalent bonding in terms of orbital overlap, giving σ and π bonds, including the concept of hybridisation to form sp, sp2 and sp3 orbitals (see also Section 14.3) c) explain the shapes of, and bond angles in, molecules by using the qualitative model of electron-pair repulsion (including lone pairs), using as simple examples BF3 (trigonal planar), CO2 (linear), CH4 (tetrahedral), NH3 (pyramidal), H2O (non-linear), SF6 (octahedral), PF5 (trigonal bipyramidal) d) predict the shapes of, and bond angles in, molecules and ions analogous to those specified in 3.2© (see also Section 14.3)

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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/lNBnCDNfJ5w 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

In this lesson we focus on the electron and how it arranges itself around the nucleus in principal quantum levels, subshells and atomic orbitals. This is lesson five in our physical chemistry series for Unit 2: Atomic Structure (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/5WDNgSCwhJQ LESSON OBJECTIVE: Understand how the electron exists in principal quantum levels and subshells, to describe the relative energies of the s, p and d orbitals and to sketch the s and p orbitals. LEARNING OUTCOMES (from the Cambridge AS Chemistry Curriculum 2019-2021): 2.3 Electrons: energy levels, atomic orbitals, ionisation energy, electron affinity a) 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 b) describe and sketch the shapes of s and p orbitals

In this lesson we focus on the rules stating how electrons fill orbitals and how to write electron subshell configuration. This is lesson six in our physical chemistry series for Unit 2: Atomic Structure (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/KbchcExPzPQ LESSON OBJECTIVE: Understand how electrons fill orbitals and to determine subshell electronic configuration for given atoms and ions. LEARNING OUTCOMES (from the Cambridge AS Chemistry Curriculum 2019-2021): 2.3 Electrons: energy levels, atomic orbitals, ionisation energy, electron affinity c) state the electronic configuration of atoms and ions given the proton (atomic) number and charge, using the convention 1s22s22p6, etc.

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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/oS6rED0MvfM 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

In this lesson we discuss how to calculate enthalpy changes using the equation ΔH=–mcΔT, specific heat capacity and the concept of calorimetry as an experimental technique. This is lesson sixteen in our physical chemistry series for Unit 5: Chemical Energetics (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/3rqVWcTXG_k LESSON OBJECTIVE: Understand how to calculate the enthalpy change of a reaction from experimental data obtained via calorimetry. LEARNING OUTCOMES (from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 5.1 Enthalpy change, ΔH c) calculate enthalpy changes from appropriate experimental results, including the use of the relationship ΔH = –mcΔT

In this lesson we discuss the solid state and the different types of lattice structures that can exist. This is lesson fourteen in our physical chemistry series for Unit 4: States of Matter (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/PN3-WqNqO4I LESSON OBJECTIVE: Investigate lattice structures responsible for the solid state. LEARNING OUTCOMES (from the Cambridge AS Chemistry Curriculum 2019-2021): 4.3 The solid state: lattice structures a) describe, in simple terms, the lattice structure of a crystalline solid which is: i) ionic, as in sodium chloride and magnesium oxide ii) simple molecular, as in iodine and the fullerene allotropes of carbon (C60 and nanotubes only) iii) giant molecular, as in silicon(IV) oxide and the graphite, diamond and graphene allotropes of carbon iv) hydrogen-bonded, as in ice v) metallic, as in copper b) discuss the finite nature of materials as a resource and the importance of recycling processes c) outline the importance of hydrogen bonding to the physical properties of substances, including ice and water (for example, boiling and melting points, viscosity and surface tension) d) suggest from quoted physical data the type of structure and bonding present in a substance

In this lesson we discuss how catalysts can increase the rate of reaction, how to represent this on enthalpy profile diagrams and Boltzmann distributions, how to define heterogeneous and homogeneous catalyst and how enzymes catalyse biochemical reactions. This is lesson twenty six in our physical chemistry series for Unit 8: Reaction kinetics (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/0a8vL4islvg LESSON OBJECTIVE: Describe how catalysts increase the rate of reaction and illustrate this on a Boltzmann distribution. Understand the difference between homogeneous and heterogeneous catalysts. LEARNING OUTCOMES (taken from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum): 8.3 Homogeneous and heterogeneous catalysts including enzymes a) explain and use the term catalysis b) explain that catalysts can be homogeneous or heterogeneous c) (i) explain that, in the presence of a catalyst, a reaction has a different mechanism, i.e. one of lower activation energy (ii) interpret this catalytic effect in terms of the Boltzmann distribution d) describe enzymes as biological catalysts (proteins) which may have specificity

In this lesson we discuss enthalpy changes, exothermic and endothermic reactions and enthalpy profile diagrams. This is lesson fifteen in our physical chemistry series for Unit 5: Chemical Energetics (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/vwg0VQHgjPs LESSON OBJECTIVE: Understand the properties of exothermic and endothermic reactions and to describe the enthalpy change of various reactions under standard conditions. LEARNING OUTCOMES (from the Cambridge International AS and A Level Chemistry (9701) 2019-2021 curriculum) 5.1 Enthalpy change, ΔH a) explain that chemical reactions are accompanied by energy changes, principally in the form of heat energy; the energy changes can be exothermic (ΔH is negative) or endothermic (ΔH is 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 (ΔH positive, i.e. bond breaking)

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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/2cIpCGNyYic 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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/L4h8ANWVDaQ 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.

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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/r2DmFuH-DBw 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)

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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/7pJw8D24J8g 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

In this lesson we discuss the particle model of states of matter, kinetic theory, the ideal gas law and the general gas equation. This is lesson twelve in our physical chemistry series for Unit 4: States of Matter (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/Z8SwQCzpLhA LESSON OBJECTIVE: Understand how to calculate and manipulate the ideal gas law equation and explain its limitations. Learning Outcomes (from the Cambridge AS Chemistry Curriculum 2019-2021): 4.1 The gaseous state: ideal and real gases and pV=nRT 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

In this lesson we give an overview of the three types of chemical bonding (ionic, covalent and metallic) and an introduction into how VSEPR theory dictates molecular geometries. This is lesson eight in our physical chemistry series for Unit 3: Chemical Bonding (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/vVPgIW91tAc LESSON OBJECTIVE: Understand how ionic, covalent and metallic bonds form. Rationalise molecular geometries using VSEPR theory. Learning Outcomes (from the Cambridge AS Chemistry Curriculum 2019-2021): 3.1 Ionic bonding a) describe ionic bonding, using the examples of sodium chloride, magnesium oxide and calcium fluoride, including the use of ‘dot-and- cross’ diagrams 3.2 Covalent bonding and co-ordinate (dative covalent) bonding including shapes of simple molecules a) describe, including the use of ‘dot-and-cross’ diagrams: (i) covalent bonding, in molecules such as hydrogen, oxygen, chlorine, hydrogen chloride, carbon dioxide, methane, ethene (ii) co-ordinate (dative covalent) bonding, such as in the formation of the ammonium ion and in the Al2Cl6 molecule c) explain the shapes of, and bond angles in, molecules by using the qualitative model of electron-pair repulsion (including lone pairs), using as simple examples BF3 (trigonal planar), CO2 (linear), CH4 (tetrahedral), NH3 (pyramidal), H2O (non-linear), SF6 (octahedral), PF5 (trigonal bipyramidal) 3.4 Metallic bonding a) describe metallic bonding in terms of positive ions surrounded by delocalised electrons

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). Included are the lesson slides and student led tasks found in this lesson video: https://youtu.be/8HqZRIaiPHM 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