Final : Question about Neutral or Ionized acid

[Rida Ismail 2E]

Does anyone understand how to do the problem where it asked if the structure was in the Neutral for Ionized form due to the pH and the Ka values on the final?

[Karyn How 1J]

For that question, you would compare the pH to the pKa of the acid to determine whether the reaction was favored more towards the neutral or ionized form. In this case, the pKa was higher than the pH indicating that the acid was found more in the neutral form.

[Gerald Bernal1I]

Another way to check if it was ionized was to use the ph value and from that plug it in to the Ka equation. pH just refers to the H+ concentration and therefore you would know the value of H+ and A- and would be able to solve for the HA value which ended up being larger than the other concentrations.

[Natalie Wang 1B]

Another way to think about it is that in the pH of 2, there are a lot of H+ ions. In equilibrium reactions, which is what happens when weak acids disassociate, an equilibrium must be maintained. Since there are a lot of H+ ions, this would cause the reaction to favor the opposite end of the acid disassociation reaction, so it would favor HA over H+ + A-. That is another reason for why HA would be neutral.