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

In this lesson we go over the subatomic particles in the atom and the concept of the nucleus. This is lesson four in our physical chemistry series for Unit 2: Atomic Structure (from the Cambridge International AS Chemistry Curriculum (9701) 2019-2021 curriculum). LESSON OBJECTIVE: Understand the properties of subatomic particles of an element including naming, mass and charge conventions for elements and isotopes. LEARNING OUTCOMES (from the Cambridge AS Chemistry Curriculum 2019-2021): 2.1 Particles in the atom a) identify and describe protons, neutrons and electrons in terms of their relative charges and relative masses b) deduce the behaviour of beams of protons, neutrons and electrons in electric fields c) describe the distribution of mass and charge within an atom d) deduce the numbers of protons, neutrons and electrons present in both atoms and ions given proton and nucleon numbers (atomic and mass numbers) and charge 2.2 The nucleus of the atom a) describe the contribution of protons and neutrons to atomic nuclei in terms of proton (atomic) number and nucleon (mass) number b) distinguish between isotopes on the basis of different numbers of neutrons present c) recognise and use the symbolism xyA for isotopes, where x is the nucleon (mass) number and y is the proton (atomic) number

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). 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 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). 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 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). 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). 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 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). 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). 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.