Answer:
[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.
