When the breathing rate is increased, the amount of carbon dioxide (CO2) in the blood decreases because more CO2 is exhaled. This reduction in CO2 leads to a decrease in carbonic acid formation in the blood, which causes the blood pH to rise, making it more alkaline. This condition is known as respiratory alkalosis. Details:

• Increased breathing rate (hyperventilation) causes excessive exhalation of CO2, lowering its concentration in the blood

• Since CO2 in the blood forms carbonic acid (H2CO3), less CO2 means less acid, resulting in fewer hydrogen ions (H+), which raises blood pH above the normal range of 7.35 to 7.45

• The shift in the bicarbonate-carbonic acid equilibrium due to decreased CO2 causes the blood to become more basic (alkaline)

• This process is a rapid respiratory compensation mechanism to regulate acid-base balance

In summary, when breathing rate increases, blood CO2 levels decrease, and blood pH increases, leading to respiratory alkalosis.