Which of the Following Is the Most Effective Buffer System

question 17

Multiple Choice

Which of the following is the most effective buffer system for a pH value of 4.45?

• A)H₂CO₃/HCO₃^- (Ka₁ for H₂CO₃ is 4.3 × 10^-7)
• B)HCO₃^-/CO₃^2- (Ka₂ for H₂CO₃ is 4.8 × 10^-11)
• C)H₂S/HS^- (Ka₁ for H₂S is 8.9 × 10^-8)
• D)HC₂O₄^-/C₂O₄^2- (Ka₂ for H₂C₂O₄ is 5.1 × 10^-5)
• E)H₃PO₄/H₂PO₄^- (Ka₁ for H₃PO₄ is 6.9 × 10^-3)

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