What is the pH of pure water at 313 K if Kw at that temperature is 2.917 x 10 -14?

Kw = [H+][OH-] [H+] = 10-pH = 10-6.17 For [OH-] remember that heat causes more water molecules to self-dissociate but for every new H+ generated, a OH- is generated as well. Therefore, the concentration of H+ and OH- is equal. [OH-] = 10-6.17 Kw = [H+][OH-] = 10-6.17 * 10-6.17 = 10-12.34