[polexia]

To maintain the pH of blood at its normal value (7.4), the amount of H₂CO₃ in the buffer is closest to:
A) 10 x amount of NaHCO₃
B) 5 x amount of NaHCO₃
C) 2 x amount of NaHCO₃
D Half amount of NaHCO₃

I plugged in the values into Henderson-Hasselbach equation:

7.4 = 6.37 + log(HCO₃ / H₂CO₃ )
1.03 =  log(HCO₃ / H₂CO₃ )
10^1.03 = HCO₃ / H₂CO₃

If the ratio is HCO₃ : H₂CO₃
Then wouldn't it be 10 : 1

...10 parts HCO₃ to 1 part H₂CO₃
I'm getting confused with this final part.

[Borek]

What you did looks OK to me.

I wonder if it is a mistake in the answers, or is it intended to be a trick question.