Introduction to Topic 6 and Topic 16

You may have already come across the factors that affect the rate of a chemical reaction before you started the IB Diploma programme but perhaps only gained a superficial knowledge about the underlying explanations. At Standard Level the programme explains what is mean by rate of reaction and its units and why concentration, temperature, surface area and adding a suitable catalyst can all affect the rate in terms of the collision theory and the Maxwell-Boltzmann distribution curves. You are also expected to understand how the rate of reaction can be determined practically by a variety of different methods. At Higher Level the importance of the rate equation and the order of reaction are stressed and students are expected to be able to propose a reaction mechanism which is consistent with the rate equation. The effect of temperature on the rate constant and the use of the Arrhenius equation to determine activation energies are also included.