## Chemistry: The Molecular Science (5th Edition)

- NaOH is a strong base, therefore: $[OH^-] = [NaOH] = 0.025M$ 1. Calculate the hydronium concentration: $[OH^-] * [H_3O^+] = Kw = 10^{-14}$ $2.5 \times 10^{- 2} * [H_3O^+] = 10^{-14}$ $[H_3O^+] = \frac{10^{-14}}{ 2.5 \times 10^{- 2}}$ $[H_3O^+] = 4 \times 10^{- 13}$ 2. Calculate the pH Value $pH = -log[H_3O^+]$ $pH = -log( 4 \times 10^{- 13})$ $pH = 12.40$ 3. Use this value to calculate the pOH: $pH + pOH = 14$ $12.40 + pOH = 14$ $pOH = 14 - 12.40 = 1.60$