Question

Ormal metabolic processes produce significant amounts of acid, sometimes up to 10 \rm mol/day, in the human body. Thus it is desirable that the buffer system for blood contain more conjugate base than acid.
Which conjugate acid-base pair is most responsible for maintaining the \rm pH of blood?
a. \rm \frac {[{PO_4}^{3-}]}{[{HPO_4}^{2-}]}.
b. \rm \frac {[{HCO_3}^{-}]}{[H_2CO_3]}.
c. \rm \frac {[{HPO_4}^{2-}]}{[{H_2PO_4}^{-}]}.
d. \rm \frac {[{CO_3}^{2-}]}{[{HCO_3}^-]}.
e. \rm \frac {[{H_2PO_4}^{-}]}{[H_3PO_4]}.

Answer 1

Answer:

The correct option is: b. \rm \frac {[{HCO_3}^{-}]}{[H_2CO_3]}

Explanation:

Blood is an important body fluid that is pumped by the heart and circulated around the body through the blood vessels.

The pH range of the blood is 7.35 to 7.45, i.e. slightly basic. The blood pH should be regulated for the proper functioning of the human body.

The buffer system that helps in maintaining the pH of the human blood is the carbonic acid (H₂CO₃) - bicarbonate ion (HCO₃⁻) buffer system.

In thus system, the pH is balanced by the weak acid, H₂CO₃ and its conjugate base, HCO₃⁻. Therefore, H₂CO₃ and HCO₃⁻ are conjugate acid-base pair.