could be presumed to take place in water that exists as H OH , it is by no means the case. In fact, even though water undergoes a slight degree of autoionization, the reaction takes place as shown above without assuming prior ionization of water. An analogous situation exists for nonaqueous solvents, and in many cases assuming that the solvent ionizes makes clear what parts of the molecule are reacting in what way. The fact that the solvent does not undergo autoionization is immaterial. Knowing what species would be produced may make it easier to predict the course of reactions in a particular solvent. One of the primary pieces of evidence that water undergoes some autoionization comes from the conductivity of pure water. The equilibrium can be written as