Question

Calculate the ph of a 0.10 m solution of hypochlorous acid, hocl. ka of hocl is 3.5×10−8 at 25 ∘c. express your answer numerically using two decimal places.

Answer 1

Answer:

4.23.

Explanation:

∵ pH = - log[H⁺].

For weak acids:

∵ [H⁺] = √(ka)(c).

∴ [H⁺] = √(3.5 × 10⁻⁸)(0.10 M) = 5.92 x 10⁻⁵.

∴ pH = - log[H⁺] = - log(5.92 x 10⁻⁵) = 4.2279 ≅ 4.23.