1. During an experiment, a student mixed 14.5mL of a 0.500M sodium fluoride solution with 15.6mL of a 0.750M hydrofluoric acid solution, the measured pH was 3.24. Calculate the pKa.
2. Calculate the pH of a solution prepared by mixing 20.5mL of a 0.500M sodium fluoride solution with 32.5mL of a 0.750M hydrofluoric acid solution.