A 3.00 gram sample of an unkown acid is dissolved in water and titrated woth 0.200 N NaOH to th Phenolphthalein endpoint. It takes 36.00 mL of base to complete this titration. A second sample of this acid weighing 3.00 grams is added to the tirated sample and the pH is 6.60. Calcualte the molar mass of the unknown acid and determine the value of Ka for this acid.