Question

Calculate the pH of a 2.0 M solution of HClO4?

Answer 1

Answer is -0.301

Explanation;

pH = -log[H⁺]

HClO₄ gives H⁺ and ClO₄⁻ as the ions by dissociation. The stoichiometric ratio between HClO₄ and H⁺ is 1 : 1. Hence, 2 M of HClO₄ solution gives 2 M of H⁺.

Hence, pH = -log(2) = -0.301

Answer 2

The compound HClO4, when placed in water, will dissociate into the ions, H+ and ClO4-. Therefore, the 2.0 M solution will also form 2.0 M H+. The pH is calculated through the equation,
pH = -log[H+]
Substituting,
pH = -log[2] = -0.3
Thus, the pH of the solution is -0.3.