Healthy human blood needs to be maintained at a pH of 7.40 for the body to function normally.
*Carbonic acid, H₂CO₃, is a weak acid which, together with hydrogencarbonate ions, HCO³⁻, acts as a buffer to maintain the pH of blood.
The pKa value for the dissociation of carbonic acid is 6.38.
Explain, in terms of equilibrium, how the carbonic acid-hydrogencarbonate mixture acts as a buffer in the control of blood pH, and calculate the [HCO³⁻] : [H2CO₃] ratio in healthy blood