Answer:
10.1 M
Step-by-step explanation:
Applying,
pH = -log(H⁺).................... Equation 1
But,
[H⁺][OH⁻] = 1×10⁻¹⁴................ Equation 2
Where [H⁺] = Hydrogen ion concentration, [OH⁻] = Hydroxyl ion concentration.
From the question,
Given: [OH⁻] = 1.25×10⁻⁴ M
Substitute into equation 2
[H⁺][1.25×10⁻⁴] = 1×10⁻¹⁴
[H⁺] = 1×10⁻¹⁴/1.25×10⁻⁴
[H⁺] = 0.8×10⁻¹⁰ M
[H⁺] = 8×10⁻¹¹ M
Also, Substitute the value of [H⁺] into equation 1
pH = -log[8×10⁻¹¹]
pH = 10.1 M