Final answer:
Insufficient acid may not achieve the desired pH change, especially if the system is buffered. The buffering capacity can absorb excess hydrogen ions, but once exceeded, the pH will change significantly. Environmental and biological systems require careful management of acid addition to avoid pH imbalances like acidosis.
Step-by-step explanation:
If an insufficient amount of acid is added in step 9 of an experiment or process, the resulting pH of the solution may not decrease to the intended level. Considering that the pH of an acidic solution is less than 7, the addition of acid should lower the pH proportionally to the amount of acid added. However, if the system is buffered, as depicted in FIGURE 14.16, a small amount of acid may have little effect due to the capacity of the buffer to absorb excess hydrogen ions. On the other hand, a substantial amount of acid may surpass the buffering capacity, leading to a significant drop in pH. For environmental compliance, a specific quantity of strong acid must be added to neutralize water, as insufficiently treated water could result in pH imbalance and acidosis when concerning biological systems.
Moreover, other variables such as the presence of salts like sulfates, phosphates, or ammonia can affect the pH by capturing hydrogen ions. These ions would not be available to react with bicarbonate ions to produce CO₂, which could result in pH imbalance, particularly acidosis in biological systems. In the case of buffers, it's important to manage the amount of acid added accurately to ensure the buffer's capacity is not overwhelmed.