## Chemistry: Molecular Approach (4th Edition)

The value of $K_w$ at $25^o C$ is $1.0 \times 10^{-14}$.
The equations for the autoionization of water and the expression for the ion product constant are in page 732, Section 16.5 The value of the constant at $25 ^{o}C$ is on the same section, in page 733. $$H_2O(l) + H_2O(l) \leftrightharpoons H_3O^+(aq) + OH^-(aq)$$ or $$H_2O(l) \leftrightharpoons H^+(aq) + OH^-(aq)$$ $$K_w = [H_3O^+][OH^-]$$ or $$K_w = [H^+][OH^-]$$ The value of $K_w$ at $25^o C$ is $1.0 \times 10^{-14}$.