Question

use the Henderson-Hasselbalch equation to calculate the pH of a buffer solution prepared by mixing equal volumes of 0.20 M NaHCO3 and 0.10M Na2CO3.(Ka=5.6x10^-11). how would you prepare NaHCO3-Na2CO3 buffer solution that has the pH of 10.40.

Answer 1

pH = pKa + log(base)/(acid)
pH = 10.25 + log (0.05/0.1)=?

10.4 = 10.25 + log b/a
b/a = ? = approx = 1.4 so
b = 1.4a or
CO3^2- = approx 1.4*HCO3^-

Answer 2

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