Increasing the volume of air that reaches the alveoli and takes part in gas exchange will cause blood pH to:

Increase

Explanation:

As CO2 enters the blood, most of it is converted to the carbonic acid in a reaction catalyzed by carbonic anhydrase. The carbonic acid dissociates into hydrogen ions and bicarbonate ions. As the H + concentration increases, the blood pH decreases. Thus, the increased partial pressure of CO2 produces a more acidic environment. Increasing the volume of air that reaches the alveoli and takes part in gaseous exchange will increase the rate of removal of CO2 from the blood. The reduced CO2 levels in the blood would increase the blood pH.