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A digital guide to the process of problem solving which highlights strengths and weaknesses, explains mistakes, reminds you about definitions and helps to clarify concepts.This section is in the initial stages of construction — any feedback welcome!


Moles: Empirical and molecular formulae

Understanding how to use moles to find empirical formula and molecular formula.


Foundation knowledge: Isotopes and relative atomic mass

Understanding the nature of isotopes and how to calculate relative atomic mass.


Foundation knowledge: Atoms and ions

Understanding the principal sub-atomic particles inside the atom and how ions arise.


An introduction to the mole

Understanding what a mole is and how to use moles to calculate mass from molar mass.

Hot pages

  • Collision theory and rates of reactionKinetics

    You are likely to have met much of this topic in your previous chemistry studies. Confidence with your recall of the collision theory and the effect of temperature, surface area and concentration upon rate of reaction is critical.

  • Rate expression and reaction mechanismKinetics

    This section is more straightforward than it at first seems. The important thing is to be comfortable in identifying the order of reaction of a reactant or catalyst from data given, whether that is in the form of a graph or numerical data.

  • Activation energyKinetics

    This is a short topic. The Arrhenius equation is given in the data book in all its relevant forms so the important thing to do is to become familiar with the equation and to ensure that you know how to plot a graph to find activation energy.

  • Measuring energy changesEnergetics

    All physical and chemical processes are accompanied by an energy change. This section explains how the enthalpy change of a chemical reaction can be determined from the effect that it has on the temperature of the surroundings.

  • Hess's LawEnergetics

    It is not always possible to measure the enthalpy change of a reaction directly. Energy cycles offer an indirect route, using the known enthalpy changes of other reactions.