For H₃PO₄, K_a1 = 7.3 * 10^-3, K_a2 = 6.2 * 10^-6, and K_a3 = 4.8 * 10^-13. An aqueous solution of Na₃PO₄ therefore would be A) neutral. B) basic. C) acidic.

Question

Quizplus · Accepted Answer

The presence of Na₃PO₄ indicates the presence of the conjugate base of a weak acid. The presence of K_a1, K_a2, and K_a3 as strong bases suggests that the weak acid was titrated with a strong base. This results in the formation of the conjugate base, OH-, which makes the solution basic. Therefore, the correct answer is B, basic.

For H3PO4, Ka1 = 7

For H₃PO₄, K_a1 = 7