Question

The pH of blood is 7.4. If the blood contain CO₂and $HCO_{3}^{-}$, what is the ratio of conjugate base to acid (H₂CO₃) to main the pH of the blood equal to 7.4 ?

Given: $pK_{a_{1}}$ of H₂CO₃ = 6.4

• A. 10
• B. $\frac{1}{10}$
• C. 100
• D. 8

Answer 1

Answer: (A)

10

Answer 2

7.4 = 6.4 + log $\frac{\lbrack HCO_{3}^{-}\rbrack}{\lbrack H_{2}CO_{3}\rbrack}$

or $\frac{\lbrack HCO_{3}^{-}\rbrack}{\lbrack H_{2}CO_{3}\rbrack}$ =10