Biochemistry The pH of body fluids is stabilized by buffer y systems. Which of the following compounds is the most effective buffer at physiologic pH? A Na2HPO4, pKa5 12.32 B NH4OH, pKa5 9.24 C NaH2PO4, pKa5 7.21 D CH3CO2H, pKa5 4.75 💡 Explanation The pH of body fluids is stabilized by buffer y systems. Which of the following compounds is the most effective buffer at physiologic pH? ✓ Correct Answer: C. NaH2PO4, pKa5 7.21