What are the pOH and pH of a 0.0125 M solution of potassium hydroxide at 25 degrees Celsius?

1. Potassium hydroxide is highly soluble and dissociates completely in dilute solution. 2. Each formula unit gives one hydroxide ion, so the hydroxide molarity is 0.0125. 3. pOH is minus the logarithm of 0.0125. 4. Write 0.0125 as 1.25 x 10^-2, so the logarithm is 0.097 minus 2, which is minus 1.903. 5. Changing the sign gives pOH = 1.903. 6. At 25 degrees Celsius pH and pOH sum to 14.00. 7. So pH = 14.00 minus 1.903 = 12.10, which is strongly basic as expected. 8. Swapping the two figures is the standard trap, and it would make a strong base look acidic. _Source: OpenStax Chemistry (CC BY 4.0), Ch 14 "Acid-Base Equilibria", section 14.2 pH and pOH_