For H₃PO₄, K_a1 = 7.3 × 10^-3, K_a2 = 6.2 × 10^-6, and K_a3 = 4.8 × 10^-13. A 0.10 M aqueous solution of NaH₂PO₄ therefore would be ________. A) neutral B) weakly basic C) weakly acidic D) strongly acidic E) strongly basic

Question

Quizplus · Accepted Answer

NaH₂PO₄ is the salt of a weak acid (H₃PO₄) and a weak base (NaOH). The solution is weakly acidic because the second dissociation constant (Ka2) is greater than the hydrolysis constant of the conjugate base.

For H3PO4, Ka1 = 7

For H₃PO₄, K_a1 = 7