A single line is seen in the 31P spectrum of a solution of sodium phosphate. The 31P chemical shifts of H2PO4‾ and HPO42– are 3.42 ppm and 5.82 ppm respectively. What is the chemical shift when the pH of the solution equals the pKa of H2PO4‾?
(A)3.41 ppm (B)3.98 ppm (C)4.33 ppm (D)4.62 ppm
D