2.8 g of KOH is dissolved in a 500 mL solution at 298 K. What is the p^H of solution ? (molar mass of KOH = 56 g/mol)

Step-by-step solution

Moles of KOH = 2.8 56 = 0.05 mol Volume of solution = 500 mL = 0.5 L Molarity of KOH = 0.05 0.5 = 0.1 M Since KOH is a strong base, it dissociates completely in water. [OH⁻] = 0.1 M = 10⁻¹ M pOH = - [OH⁻] = - (10⁻¹) = 1 At 298 K, pH + pOH = 14 pH = 14 - 1 = 13 Answer: 13