Question

how a buffer works

after drinking a great deal of coffee (ph 5), a human’s blood buffering system would need to ______ as the coffee was digested to lower the level of acid present in the blood stream.

multiple choice

release h⁺

release oh⁻

release h⁺ and take up oh⁻

take up oh⁻

take up h⁺

Explanation:

Coffee is acidic (pH 5), so it adds $\text{H}^+$ to the blood. A buffer system in blood (like bicarbonate buffer) works to maintain pH by taking up excess $\text{H}^+$ (from the acid) to neutralize it and prevent blood pH from dropping too much. Releasing $\text{H}^+$ or $\text{OH}^-$ in this context would worsen acidity; taking up $\text{OH}^-$ is not relevant here as the issue is excess $\text{H}^+$. Thus, the blood buffer takes up $\text{H}^+$.

Answer:

E. take up $\text{H}^+$