Final answer:
The pH of a 0.25 M solution of a weak acid with a dissociation constant of 1.1 × 10-6 can be calculated using the formula pH = -log[H+]. Plugging in the values gives a pH of 3.26.
Step-by-step explanation:
The pH of a solution of a weak acid can be calculated using the dissociation constant (Ka) of the acid and the initial concentration of the acid. In this case, the Ka of the acid is 1.1 × 10-6 and the concentration is 0.25 M. The pH can be calculated using the formula: pH = -log[H+]. In this case, [H+] can be calculated using the equation [H+] = √(Ka * C), where Ka is the dissociation constant and C is the concentration of the acid. Plugging in the values gives [H+] = √(1.1 × 10-6 * 0.25) = 5.52 × 10-4. Taking the negative logarithm of this value gives the pH: pH = -log(5.52 × 10-4) = 3.26. Therefore, the pH of the 0.25 M solution of the weak acid is 3.26.