Kw at different temperatures

The ion product of water, Kw, measures how much water naturally splits into hydrogen and hydroxide ions. At standard room temperature (about 25°C), Kw is constant at 1.0 × 10⁻¹⁴, meaning water produces very few ions. As temperature increases, water molecules gain energy and more of them split into ions, so Kw becomes larger. This means higher temperatures lead to more ion separation, making water slightly more conductive. Conversely, at lower temperatures, fewer molecules split, and Kw decreases, resulting in fewer ions in the water.