The following figure illustrates the action of a HF and F ^- buffer where the sizes of the boxes are proportional to the concentrations of HF and F ^- in solution. If you add hydronium until all of the F ^- is converted into HF and then add a little more hydronium, what is observed? A) The pH increases. B) The pH decreases. C) The pH stays the same. D) The solution will be neutralized. E) The pH changes, but it is not possible to determine how it will change.

Question

Quizplus · Accepted Answer

When hydronium is added, it reacts with the FF1F1F1S1^F1F1F10 buffer to convert all of it into HF. However, if more hydronium is added after this point, it will cause the pH to decrease because the excess hydronium will protonate the remaining HF molecules. This will shift the equilibrium towards the formation of H3O+ and F- ions, resulting in a decrease in pH. Therefore, the correct answer is B.

The Following Figure Illustrates the Action of a HF and F