The ionic product of water is 0.11 x ${{10}^{-14}}$ at 273 K, 1 x ${{10}^{-14}}$ at 298 K and 7.5 x ${{10}^{-14}}$ at 373. Deduce from this data whether the ionization of water to Hydrogen and Hydroxide ion is exothermic or endothermic?

According to the data the value of is increasing with temperature. Therefore according to Le-Chatelier’s principle the ionisation of water is endothermic.