Question

The dibasic compound B (pK_b1 = 4.00, pK_b2 = 8.00) was titrated with 1.00 M HCl. The initial solution of B was 0.100 M and had a volume of 100.0 mL. Find the pH after 3.7 mL of acid are added.

Answer 1

0 100 ml 0.100 M B = (100x0.100) = 10 mmol..Bi A 3.7 ml 100M HU= . 37 mmol. He.. . After reaction there will be 3.7 mmol. salt and Clo-3.7) = 6.3 mmol unreacted 'B' weak base, so the solution is a buffer and the pot of the's buffer pot = pkb, tlog Base no [salt? = 4 + log ( 3 7/2 . = 3.77 - pH = 14-pOH = 14 -3.77) = 10:23 The pH of the solution after addition of 3.7 ml 1.00M HU = 10:23 Cans)