Titration of 664 mg of a pure organic carboxylic acid, H2A, showed a rapid change in pH at 40 ml. an β AITS & Test Series Chemistry Question
Question
Titration of 664 mg of a pure organic carboxylic acid, H2A, showed a rapid change in pH at 40 ml. and at 80 ml of 0.1 M NaOH titrant. When 40 ml. of NaOH was added, the pH was 5.85 and at 60 ml of NaOH the pH was 8.08. Which of the following statements are correct

π‘ Solution & Explanation
Since 4 milli mole of NaOH was required to reach first equivalence point, the molecular wt. was 664 166 4 mg m mol ο½ 60 ml of NaOH is represented by a point midway to second equivalence point, at which pH = Pka2 = 8.08 At the first equivalence point, pH = 5.85 = 1 2 2 Pka Pka ο« ο Pka1 = 3.62 AITS-FT-VII-(Paper-2)-PCM (Sol.)-JEE(Advanced)/18 FIITJEE Ltd., FIITJEE House, 29-A, Kalu Sarai, Sarvapriya Vihar, New Delhi -110016, Ph 46106000, 26569493, Fax 26513942 website: www.fiitjee.com 10