1. Understanding KOH

* KOH is potassium hydroxide, a strong base. This means it completely dissociates in water.

* The dissociation reaction is: KOH (aq) → K⁺ (aq) + OH⁻ (aq)

2. Finding the Hydroxide Ion Concentration ([OH⁻])

* Since KOH is a strong base, the concentration of hydroxide ions ([OH⁻]) is equal to the initial concentration of KOH: [OH⁻] = 10⁻⁵ M

3. Calculating pOH

* pOH is a measure of hydroxide ion concentration:

pOH = -log[OH⁻]

pOH = -log(10⁻⁵) = 5

4. Calculating pH

* The relationship between pH and pOH is: pH + pOH = 14

* Therefore: pH = 14 - pOH = 14 - 5 = 9

Answer: The pH of a 10⁻⁵ M KOH solution is 9.