## Chemistry: The Central Science (13th Edition)

$[OH^-] \approx 3.1623 \times 10^{-3}$
1. Find the pOH of the solution: $pH + pOH = 14$ $11.5 + pOH = 14$ $pOH = 14 - 11.5$ $pOH = 2.5$ 2. Calculate the concentration of $OH^-$. $[OH^-] = 10^{-pOH}$ $[OH^-] = 10^{-2.5}$ $[OH^-] \approx 0.0031623$