Question

The buffer action of blood is due to the presence of 

(a) HCl and NaCl

(b) Cl^- and CO\(^{2-}_3\)

(c) Cl^- and HCO\(^-_3\)

(d) HCO\(^ -_3\) and H₂CO₃

Answer 1

(d) HCO\(^ -_3\) and H₂CO₃

Human blood contains a buffer of carbonic acid (H₂CO₃) and bicarbonate anion (HCO\(^ -_3\)) in order to maintain blood pH between 7.35 and 7.45, as a value higher than 7.8 or lower than 6.8 can lead to death. In this buffer, hydronium and bicarbonate anion are in equilibrium with carbonic acid.