What is the pH of a 1.9 M solution of HClO4?

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.