A friend asks the following: \"Consider a buffered solution made up of the weak
ID: 869483 • Letter: A
Question
A friend asks the following: "Consider a buffered solution made up of the weak acid HA and its salt NaA. If a strong base like NaOH is added, the HA reacts with the OH- to make A-. Thus, the amount of acid (HA) is decreased, and the amount of base (A-) is increased. Analogously, adding HCl to the buffered solution forms more of the acid (HA) by reacting with the base (A-). How can we claim that a buffered solution resists changes in the pH of the solution?" How would you explain buffering to your friend?
Explanation / Answer
When we add a base to the buffer solution, HA reacts and same amount of A- would be formed. so the ratio of
[A-] / [HA] always very small value and more over log [A-] / [HA] is very less. Hence the change in the pH by addition of acid or base it maximum changes in the range of pH +/- 1.
The same explanation is applied to solution when changes occurs addition of base.