Doubling the respiratory rate for under a minute, by removing extra CO2, would increase blood pH by approximately:

1. Breathing rate directly controls how much CO2 is exhaled and, therefore, blood pH. 2. A specific example: doubling respiratory rate briefly removes extra CO2. 3. This is stated to raise blood pH by 0.2. 4. 7.4 is the normal blood pH value itself, not a pH change, so it is ruled out. 5. So 0.2 is the correct pH increase. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 26 "Fluid, Electrolyte, and Acid-Base Balance", p.1267 §Respiratory Regulation of Acid-Base Balance_