Calculate the pH of a 0.15 M solution of HOI. (K_a = 2.3 x 10^-11) A) 5.73 B) 5.53 C) 5.33 D) 5.13 E) None of the above

Question

Quizplus · Accepted Answer

The pH of a solution can be calculated using the formula pH = -log[H+], where [H+] is the concentration of hydrogen ions in the solution. For a weak acid like HOI, we first need to calculate the concentration of hydrogen ions produced when HOI dissociates in water. The dissociation of HOI can be represented as HOI ⇌ H+ + OI-. The equilibrium constant for this reaction (Ka) is given as 2.3 x 10^-11. Using the formula for the equilibrium constant, Ka = [H+][OI-]/[HOI], and assuming that the concentration of H+ and OI- produced is x, we have 2.3 x 10^-11 = x^2 / (0.15 - x). Assuming x is much smaller than 0.15 M, we can approximate this to 2.3 x 10^-11 = x^2 / 0.15. Solving for x gives x ≈ 1.87 x 10^-6 M. Then, pH = -log[H+] = -log(1.87 x 10^-6) ≈ 5.73.

Calculate the PH of a 0