Question

What is the H3O* lon concentration in an aqueous solution having an OH" concentra of 1.0 x 10-2 M?_ ___ What is the pH?

Answer 1

[H₃O⁺] = 1.0 x 10⁻¹² M

pH = 12

Step-by-step 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