A brief history of atomic structure and the scientists who worked on it. |
Discussion how the structure of the atom has changed from Thomson's Plum Pudding model, through Rutherford's nuclear atom and the Bohr atom. An introduction to the quantum mechanical model of the atom and the work of Max Planck, Louis De Broglie, Erwin Schrödinger and Heisenberg’s Uncertainty Principle. |
Absorption and emission spectra |
Discussion on how emission and absorption spectra helped scientists work out the internal structure of atoms. This page discusses the hydrogen emission spectrum and how Bohr used his "new" ideas on the internal structure of the atom and the quantum theory to explain the emission spectrum for the hydrogen atom. |
Electron shells, sub-shells and orbitals |
An introduction to quantum mechanical model of the atom which includes sub-levels and orbitals, the shapes of the s, p and d orbitals is also discussed. |
The aufbau principle |
A brief explanation with examples on how to work out the electronic configuration
for atoms including transition metals using the Pauli Exclusion Principle and Hund's rule. |
Ion formation |
Explanation with examples on how to work out the electron configuration of metal and non-metal ions. |
Trends in atomic radii |
Description and explanation on the trends and patterns in the sizes of atoms across a period and down a group in the periodic table. |
Trends in the ionisation energy for period 3 elements |
Examples with detailed explanations to discuss the patterns and trends in the ionisation energies for the period 3 elements. |
Trends in the ionisation energy for group 2 elements |
Examples to show the trends in the ionisation energies for the group 2 elements. Also covered is the use
of ionisation energies as evidence for the existence of shells and sub-shells with atoms. |
Types of intermolecular bonding. |
Explanation of the difference between intramolecular and intermolecular bonding and a brief outline of the three different types of intermolecular forces or bonds. |
Van der Waals bonding/dispersion forces |
Explanation with examples on how Van der Waals forces (London dispersion forces) originate and their effects on the physical properties of substances. |
Dipole-dipole interactions |
Introduction to intermolecular bonding and dipole-dipole interactions. |
Hydrogen bonding |
Explanation of hydrogen bonding with examples of molecules which contain H-bonds. Discussion on the affects of
hydrogen bonding on the physical properties of molecules. |
Intermolecular bonding and physical properties |
This page explains and gives examples of how the types of intermolecular bonding present between molecules can affect physical properties such as melting/boiling points, solubility, viscosity and surface tension in liquids.. |
Enthalpy changes |
Discussion with examples on the differences between open and closed systems. The meaning of the term enthalpy is explained with
some worked examples. Recap on endothermic and exothermic reactions. |
Enthalpies of combustion, formation and standard states |
Discussion with examples on enthalpies of combustion and formation. Introduction to the idea of standard enthalpy
changes and standard states. |
Hess's Law |
Explanation with examples on how to carry out Hess's law types questions using enthalpies of formation and combustion. |
Enthalpy changes using mean bond enthalpies |
Discussion with examples on how to use mean bond enthalpies to calculate enthalpy changes for reactions. |
Calorimetry |
Explanation and worked examples on how to calculate enthalpy changes using asimple calorimeter.
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Enthalpy changes in solution |
Details on how to calculate enthalpy changes for reactions taking place in solution e.g. neutralisation and displacement reactions. |
Oxidation, reduction and redox equations |
Examples on how to write half-equations for redox reactions. Re-cap from gcse on the meaning of the terms oxidation, reduction, reducing agent and oxidising agent. |
Examples of simple redox equations and introduction to oxidising agents |
Examples on how to write simple half-equations to show oxidation and reduction in chemical reactions. Examples include
metal acid reactions and combustion reactions. Examples on oxidation/reduction/redox and introduction to common oxidising agents. |
Oxidation numbers |
Introduction to oxidation numbers with examples on how to work them out for a range of compounds. Discussion of the variety of
oxidation numbers for transition metals, including vanadium and chromium. |
Redox equations and oxidising agents |
Examples with half-equations to show the use of potassium dichromate and potassium permanganate as oxidising agents in redox reactions. Help given on
how to deal with complex redox equations with example problems and answers provided. |
Halogens- general properties |
Overview of the basic properties and reactions of the halogens, including: trends in reactivity, solubility, electronegativity and reactions with metals and non-metals. |
Halogens- oxidising ability |
The trends in the oxidising ability of the halogens is discussed along with examples of halogens acting as oxidising agents in
displacement reactions. |
Halide ions as reducing agents |
Description of the trends in the reducing abilities of the halide ions with examples and explanations. |
Testing for halide ions |
Details of the silver nitrate test and discussion on the solubilities of halide ions in ammonia solutions. |
Disproportionation reactions |
Examples of disproportionation reactions using the reactions of chlorine with water and sodium hydroxide as examples. Discussion on why water is chlorinated along with the advantages and disadvantages of adding chlorine to drinking water. |
Sigma and pi bonds |
Explanation of the difference between sigma and pi bonds, with examples given to show how each type of bond
is formed. |
Stereoisomers |
Description of geometric isomers and the cis/trans, E-Z naming systems with a few examples of each. |
Cahn-Ingold-prelog rules for naming alkenes |
A brief outline is given of how the Cahn-Ingold-Prelog rules are used to name substituted alkene molecules.
The limitations of the cis/trans naming system for disubstituted alkene molecules is also discussed. |
Alkenes and addition reactions |
Discussion of the mechanism of electrophilic addition reactions to alkenes using bromine and bromine water as
examples. |
Further Addition reactions |
Discussion on how alkenes can be used to produce halogenalkanes by reaction with hydrogen halides and also
how alcohols can be produced by direct hydration and by the reaction of an alkene with concentrated sulfuric acid.
Brief discussion on how alkenes can be oxidised to form diols using potassium permanganate as an oxidising agent. |
Predicting products of addition reactions to unsymmetrical alkenes |
Discussion with examples on how to predict the major and minor products of addition reactions to unsymmetrical alkenes. Examples
using Markovnikov's rule. |
Hydrogenation of unsaturated molecules |
A discussion of the mechanism and uses of hydrogenation of carbon carbon double bonds (C=C) in fats and oils. |
Fermentation, biofuels and direct hydration |
Outline of how alcohol is made by fermentation and the pros and cons of biofuels is discussed. Finally the production
of ethanol by direct hydration is contrasted with fermentation. |
Reactions of alcohols |
Brief discussion of the reactions of alcohols, this includes products of combustion and the reactions of alcohols with
metals such as sodium. |
Oxidation of alcohols |
Explanation of the differences between primary, secondary and tertiary alcohols and the products of
the oxidation of each class of alcohol. |
Dehydration of alcohols |
Discussion of the elimination mechanism for the dehydration of alcohols to form alkenes.. |
Halogenalkanes from alcohols |
Discussion on how to prepare halogenalkanes from primary, secondary and tertiary alcohols. An experimental method is
outlined for the formation of a tertiary halogenalkane from a tertiary alcohol.
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