Answer:
[H₃O⁺] = 1.0 x 10⁻¹² M
pH = 12
Explanation:
The H₃O⁺ concentration is related to the OH⁻ concentration through the water autoionization constant Kw:
Kw = [H₃O⁺][OH⁻] = 1.0 x 10⁻⁻¹⁴
[H₃O⁺] = (10⁻⁷)/[OH⁻] = (1.0 x 10⁻¹⁴)/(1.0 x 10⁻² M) = 1.0 x 10⁻¹² M
The pH is found using the following equation:
pH = -log([H₃O⁺]) = -log(1.0 x 10⁻¹²) = 12
