If the concentration of OH - in a sample of seawater is 2.0x10-6 M, then calculate the concentration of H3O and the pH. Classify the solution as acidic, basic, or neutral.

[H₃O⁺] = 5.0 * 10⁻⁹ M

pH = 8.3

Basic

Explanation:

The concentration of OH⁻ in a sample of seawater is 2.0 * 10⁻⁶ M.

We can find the concentration of H₃O⁺ using the following expression.

[H₃O⁺] * [OH⁻] = Kw = 1.0 * 10⁻¹⁴

[H₃O⁺] = 1.0 * 10⁻¹⁴ / [OH⁻]

[H₃O⁺] = 1.0 * 10⁻¹⁴ / 2.0 * 10⁻⁶

[H₃O⁺] = 5.0 * 10⁻⁹ M

The pH is:

pH = - log [H₃O⁺]

pH = - log 5.0 * 10⁻⁹

pH = 8.3

Since pH > 7, the solution is basic.