Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

An amphoteric salt is one that contains an anion that can act as either an acid

ID: 900391 • Letter: A

Question

An amphoteric salt is one that contains an anion that can act as either an acid or a base in water. Baking soda, NaHCO_3, is an example. By combining the ionization and hydrolysis reactions of the anion, we get the principle reaction that occurs when this salt is dissolved in water. 2HCO_3^+ (aq) CO_3^2- (aq) + H_2 CO_3(aq) The pH for such a solution is given by pH = p K_a1 + p K_a2/2 where K_a1 and K_a2 are the ionization constants of the acid (in this case, H_2 CO_3). Note that the pH of the solution is independent of the salt concentration. Calculate the pH of a NaHCO_3 solution.

Explanation / Answer

Please verify that you have the same values for

pKa1 = 6.37

pKa2 = 10.32

Then

pH = (6.37+10.32) / 2 = 8.34

Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Drop an Email at
drjack9650@gmail.com
Chat Now And Get Quote