Final answer:
The question deals with the effect of adding NaOH to a buffer and how it impacts the pH level of the mixture. Buffer systems resist changes in pH upon the addition of strong acids or bases, by neutralizing added OH- ions without causing large pH shifts.
Step-by-step explanation:
The subject of the question is the addition of NaOH to a buffer solution containing (CH3)2NH2 and how it affects the pH, which maintains a relatively constant value due to the buffer action. When NaOH is added, the OH- ions from NaOH react primarily with the acid component of the buffer. In a buffer mixture, a significant change in pH is resisted because the buffer components are able to neutralize added acids or bases. This neutralization occurs via an acid-base reaction described as:
HC2H3O2 (aq) + OH- (aq) → H2O (l) + C2H3O2- (aq)
Increasing the concentration of the buffer enhances its capacity to maintain the pH when strong bases like NaOH are added. However, if too much strong base is added, the buffer capacity can be exceeded, resulting in significant pH changes.