Biochemistry In order to keep blood pH at 7.4, the HCO3: H2CO3 ratio should be: A 2:01 B 5:01 C 10:01 D 20:01 💡 Explanation In order to keep blood pH at 7.4, the HCO3: H2CO3 ratio should be: ✓ Correct Answer: D. 20:01