Determining pH of Salts

[ALee1G]

When determining the pH of a salt, it is usually determined by the strong component in a salt. For example, NH4Cl is an acidic salt because the anion is part of a strong acid (HCl) and the cation is from a weak base (NH3). What is the pH of the salt when both the cation and anion are from a weak acid and base?

[jamesw27]

When both the cation and anion are weak bases or acids, whether the salt is basic or acidic depends on the specific weak base or acid. The salt will be more acidic or basic depending on which base or acid is relatively stronger as the conjugate would be weaker.

[Lena Jabourian 1C]

I think it has to do with the conjugate seesaw idea. For instance, if there is anion (ex: Cl-) that's coming from a strong acid (HCl), the conjugate base is weak and therefore won't affect the pH. Like you said, since this component is weak, the other ion of the salt would be the thing that's determining the pH. In the examples we've been provided with, at least one component of the salt is the conjugate acid/base of a strong acid/base so I believe if both components of the salt are from a weak acid/base, we'd be provided with Ka or Kb and can solve the pH that way.

[406003397]

When both the cation and anion in a salt come from weak acids and bases, the pH of the solution depends on the relative strengths of the weak acid and base that form the salt. If the weak base is stronger than the weak acid, the solution will be basic; if the weak acid is stronger, the solution will be acidic.