Answer
- The second solution (2) has the highest pH;
- The first solution has the greater $HF$ dissociation;
Work Step by Step
- The presence of $F^-$ ions in the second solution makes its pH greater than the pure $HF$ one, because the fluoride ion can act as a base.
- Due to the common ion effect, the presence of $F^-$ in the second solution restricts the dissociation of $HF$, because it moves the equilibrium to the left side:
$HF(aq) + H_2O(l) \lt -- \gt F^-(aq) + H_3O^+(aq)$
Therefore, the first solution has the greater $HF$ percent dissociation.
