A 58-year-old man with chronic obstructive pulmonary disease (COPD) presents with shortness of breath, confusion, and drowsiness. Arterial blood gas (ABG) analysis reveals: pH = 7.28 (acidic) PaCO₂ = 55 mmHg (elevated) HCO₃⁻ = 24 mEq/L (normal) The physician explains that water is critical for acid-base homeostasis, as it participates in buffering systems that regulate blood pH. Which of the following best describes water’s role in acid-base balance?
