A solution is prepared by titrating a 100.0 mL sample of 0.10 M HF (Ka = 7.2 × 10-4) with 0.10 M NaOH

a. Does the solution contain a strong acid with a strong base, a strong acid with a weak base, a weak acid with a strong base, or a weak acid with a weak base?

b. Estimate the pH at the equivalence point. Will it be equal to 7, greater than 7, or less than 7?.
c. What is the pH after 20.0 mL of the 0.10 M NaOH is added? Show all calculations.