Answer:
12
Explanation:
Ba(OH)₂ is a strong base that dissociates according to the following equation.
Ba(OH)₂(aq) → Ba²⁺(aq) + 2 OH⁻(aq)
The molar ratio of Ba(OH)₂ to OH⁻ is 1:2. Then, the concentration of OH⁻ is 2 × 5.00 × 10⁻² M = 0.100 M
The ionic product of water (Kw) is:
Kw = 9.5 × 10⁻¹⁴ = [H⁺].[OH⁻] = [H⁺].(0.100)
[H⁺] = 9.5 × 10⁻¹³ M
The pH is
pH = -log [H⁺] = -log 9.5 × 10⁻¹³ = 12
