Water is important to the chemistry of acids and bases as it is amphoteric: able to act as an acid or a base. The self–ionisation of water and the constant, Kw, the equilibrium constant for this process, are vital concepts to grasp as a platform for further studies of acids and bases.
After working through this topic you will be able to:
- explain what is meant by the ionisation of water, how it relates to pH, and what factors affect it;
- consider students difficulties with equilibria and applying these ideas to the ionic product of water and pH;
- use effective strategies and activities to support students’ understanding of Kw and its link with pH.