The PH of Blood Is 7

Multiple Choice

The pH of blood is 7.35. It is maintained in part by the buffer system composed of carbonic acid (H₂CO₃) and the bicarbonate (hydrogen carbonate, HCO₃⁻) ion. What is the ratio of [bicarbonate]/[carbonic acid] at this pH? For carbonic acid, K_a1 = 4.2 × 10⁻⁷.

A) [bicarbonate]/[carbonic acid] = 0.11
B) [bicarbonate]/[carbonic acid] = 0.38
C) [bicarbonate]/[carbonic acid] = 2.65
D) [bicarbonate]/[carbonic acid] = 9.4
E) None of these choices are correct.