Kw=1.0E-14. A sample of 0.1355g of an unknown monoprotic acid was dissolved in 25.0mL of water and titrated with 0.0950 M NaOH. The acid required 19.3mL of base to reach the equivalence point, The molar mass of the acid is 73g/mol. What is the Ka, if after adding 12.0mL of base, the pH was measured to be 5.10.