Following Self-Ionisation

The following table gives the temperature dependence of K. What is the sign of AH for the self ionisation Find the pH of pure water at these temperatures. 

In many systems the ionisation of the solute in one or both phases or the association of the solute in one of the solvents complicates the calculation of partition coefficient. As early as 1891, Nemst stressed the fact that the partition coefficient as a function of concentration would be constant only if a single molecular species was involved. If the solute forms aggregates or otherwise self-associates, the following equilibrium between the two phases 1 and 2 occurs when dimerisation occurs in phase 2 ... 

The secondary electrons produced can also ionise the gas. The phenomenon becomes self-sustained if following condition is met ... 

---