Kw = [H+][OH-] = 1.86 x 10^-16 at 25 °C
Where Kw is the ionic product constant of water, [H+] is the concentration of hydrogen ions, and [OH-] is the concentration of hydroxide ions.
At higher temperatures, Kw increases, which means that the concentration of H+ and OH- ions in water increases. This is because the higher the temperature, the more energy the water molecules have, and the more likely they are to break apart into H+ and OH- ions.
Conversely, at lower temperatures, Kw decreases, which means that the concentration of H+ and OH- ions in water decreases. This is because the lower the temperature, the less energy the water molecules have, and the less likely they are to break apart into H+ and OH- ions.
The temperature dependence of Kw has important implications for many chemical and biological processes that occur in water. For example, the pH of water is determined by the concentration of H+ ions, and since Kw is temperature-dependent, so too is pH. This can have a significant impact on the behavior of enzymes and other proteins that are sensitive to pH changes.
In summary, the ionic product constant of water is temperature-dependent because the equilibrium concentration of H+ and OH- ions in water changes with temperature. This has important implications for many chemical and biological processes that occur in water, including the pH of water and the behavior of enzymes and other proteins.
