Calculate the pH of a solution that contains 3.9 × 10^-4 mol L^-1 H₃O⁺ at 25 °C. A) 4.59 B) 3.41 C) 10.59 D) 9.41 E) 0.59

Question

Quizplus · Accepted Answer

The first step is to write the chemical equation for the dissociation of the acid:

HSO4^- ⇄ H+ + SO4^2-

Since the acid is a monoprotic acid (it can donate only one proton), the initial concentration of H+ is equal to the concentration of acid. Therefore, [H+] = 3.9 × 10^-4 M.

The pH is defined as the negative logarithm of the hydrogen ion concentration:

pH = -log[H+]

Substituting the value of [H+] gives:

pH = -log(3.9 × 10^-4) = 3.41

Therefore, the best choice is B.

Calculate the PH of a Solution That Contains 3