The pH of body fluids is stabilized by buffer y systems. Which of the following compounds is the most effective buffer at physiologic pH?
Ans. C.NaH2 PO4 ,pKa5 7.21In any fluid, maximum buffering action is achieved by the acid whose pKa most nearly approximates the pH of the fluid. Physiologic pH is about 7.4, so that among those buffers listed in the question, NaH2 PO4 is the most effective.
Na2HPO4, pKa5 12.32
NH4OH, pKa5 9.24
NaH2PO4, pKa5 7.21
CH3CO2H, pKa5 4.75
Miscellaneous (Bio-Chemistry)