Final answer:
The pH of a buffer solution would remain relatively constant even if the solution is concentrated by boiling off water or diluted by adding distilled water. Significant changes would only occur if the buffer's capacity is surpassed.
Step-by-step explanation:
The question refers to what would happen to the pH of a 1 N acetic acid buffer solution if either 0.5 liters is boiled off, or if 0.5 liters of distilled water is added.
Boiling off 0.5 liters of the buffer solution would concentrate the buffer components, however, since it's a buffer solution, the pH should not significantly change. A buffer system, consisting of an acid and its conjugate base, is established to resist changes in pH upon the addition or removal of small amounts of acid or base. But, boiling off half of the solvent would greatly concentrate the buffer to a point where we could exceed its buffering capacity.
Conversely, adding 0.5 liters of distilled water to the buffer would dilute the buffer. However, the change in the buffer's pH would be minimal due to its capacity to resist changes in pH upon dilution, especially if the buffer is within its optimal buffering range and the buffer capacity is not surpassed.
Buffer solutions displaying minimal pH changes when dilute acids or bases are added are vital in many biological and chemical applications. They maintain pH within a narrow range, necessary for processes sensitive to pH changes.