Problem: AcidKaCBKbH2CO34.2 x 10-7HCO3-2.4 x 10-8HCO3-4.8 x 10-11CO32-2.1 x 10-4You are to prepare a "carbonate" buffer with pH of 10.35. You are given carbonic acid (H2CO3), sodium hydrogen carbonate (NaHCO3), and sodium carbonate(Na2CO3).H2CO3 + H2O ⇌ H3O+ + HCO3- HCO3- + H2O ⇌ H3o+ + CO3-CO32- + H2O ⇌ HCO3- + OH-a) Using the information in the chart about Ka/Kb values, which species will you use? Explain your choice?b) Which component will be present in the larger amount?c) You are given a 0.025 M solution of the acid and a 0.025 M solution of the conjugate base. Calculate how many mL of each you would use to make the buffer.

FREE Expert Solution

The maximum buffering capacity of a solution is when the pH of the solution is equal to pKa and the buffer range of a solution is pH = pKa ± 1

 maximum buffering capacity:              pH = pKa
 buffering range:              pH = pKa ± 1


pKa=-log Ka


Prepare a "carbonate" buffer with pH of 10.35:

a) Using the information in the chart about Ka/Kb values, which species will you use? Explain your choice?

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Problem Details
AcidKa
CBKb

H2CO34.2 x 10-7
HCO3-2.4 x 10-8


HCO3-4.8 x 10-11
CO32-2.1 x 10-4


You are to prepare a "carbonate" buffer with pH of 10.35. You are given carbonic acid (H2CO3), sodium hydrogen carbonate (NaHCO3), and sodium carbonate(Na2CO3).

H2CO3 + H2O ⇌ H3O+ + HCO3- 

HCO3- + H2O ⇌ H3o+ + CO3-

CO32- + H2O ⇌ HCO3- + OH-

a) Using the information in the chart about Ka/Kb values, which species will you use? Explain your choice?

b) Which component will be present in the larger amount?

c) You are given a 0.025 M solution of the acid and a 0.025 M solution of the conjugate base. Calculate how many mL of each you would use to make the buffer.

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