Question

7. Which of the two solutions below has a higher buffering capacity? Explain why one solution has a better ability to resist changes in pH. (Hint: Consider what makes a good buffer and pay special attention to the arrows used in the reactions.) Solution A: This solution is prepared by combining equal amounts of a weak acid with ts conjugate base, resulting in the expression below: Solution B: This solution is prepared by combining equal amounts of a strong acid with its conjugate base, resulting in the expression below: HA(aq)H20)A(aq)H3O (aq) HX(aq) H20()X(a) H3O (aq)

Answer 1

Solution A is reversible reaction. That is, the forward and backward reaction is happening. When an acid is added, forward reaction will occur more and thus resist the pH change. If base is added, then the backward reaction will proceed and resist the pH change. Thus, solution A shows higher buffering capacity  

Solution B is an irreversible process. Addition of an acid or a base will definitely change the pH.

Solution A has higher buffering capacity than solution B.