第三部份：計算問答題（共60分） 1 . Describe and explain how to use a titration method to determine the analytical concentration CHA and the pKa value of a weak acid HA. Define all the quantities used in your answer. (20%)

(c) (5%) What is the Gibbs free energy of freezing water at -10°C? (Molar melting enthalpy of ice: △mH° = 5619 J mol -1at–10°C, △mH° = 6008 J mol-¹ at 0°C; molar heat capacity: ice Cp,m=37.66 J mol-¹K-¹, water Cp,m-75.38 J mol¹K¹)