Which Combination May Be Used to Prepare a Buffer Having

Multiple Choice

Which combination may be used to prepare a buffer having a pH of 8.8? K_a= 7 × 10^-3 for H₃PO₄; 8 × 10^-8 for H₂PO₄^-; 5 × 10^-13 for HPO₄^2-

A) NaH₂PO₄ only
B) NaH₂PO₄ and Na₂HPO₄
C) Na₃PO₄ and Na₂HPO₄
D) NaHPO₄ and H₃PO₄
E) H₃PO₄ and Na₃PO₄