Understanding NaOH

* NaOH is a strong base, meaning it completely dissociates in water. This means that a 0.15 M NaOH solution will produce 0.15 M of hydroxide ions (OH-).

Calculating pOH

* pOH = -log[OH-]

* Substitute the concentration of hydroxide ions: pOH = -log(0.15)

* Calculate: pOH ≈ 0.82

Calculating pH

* pH + pOH = 14 (at 25°C)

* Rearrange to solve for pH: pH = 14 - pOH

* Substitute the calculated pOH: pH = 14 - 0.82

* Calculate: pH ≈ 13.18

Therefore, the pH of a 0.15 M NaOH solution is approximately 13.18.