Water Equilibrium (Kw)

• Water equilibrium (Kw)

  • can help us to make a direct connection between the [H3O+] and [OH-]. At standard conditions, water is an eq reaction:
  • 2 H2O(l) ⇌ H3O+ + OH- Kc = 1.0 x 10^-14
• Kw = [OH-][H3O+]

  1.0 x 10^-14 = [OH-][H3O+]
• can use Kw as a way to convert between the [H3O+] and the [OH-]:

  Kw = [H3O+][OH-] = 1.0 x 10^-14

  • Note: because water is in equilibrium, the pH of water changes with temperature