Question

The pK) values for the dibasic base B are pKb1 = 2.10 and pKb2 = 7.57. Calculate the pH at each of the points in the titration of 50.0 mL of a 0.60 M B(aq) solution with 0.60 M HCl(aq). What is the pH before addition of any HCI? pH What is the pH after addition of 25.0 mL HCI? pH = What is the pH after addition of 50.0 mL HCI? What is the pH after addition of 75.0 mL HCI? pH = What is the pH after addition of 100.0 mL HCI? pH =

Answer 1

. 50x/0-3 - 03 Moly given pkb i = 2.10 , pk h = 7.57 Moles of B (aq) = Mularity & Volume = 0.6 X 5oxló Molarity of Melaql= o-com (6) before addition of me, het Base be Bo/ Bom Bhi Bouit touI,Bon - Broh o.f. x x xty | xy y xty, Khiz 16-21 _ 7.94 x 103 che = 10 757 2.7x10-8 (ch, the ::x>>y (x+yxx) -) x² + x(7.94 x 10- 3 - 7-94 x 0.6 x 10 3 - 0 x = -7.94 X10 3 + J (7.94 klo ? j? 4x 4.76 xlo 3 + X : -7.9 uxlo / 19.04xlo 3 + x 2 -3.97X163 +5X1.38x102 * x2 169-4)x10? 65xlo? - asxlo uodes i platilo -log 165x16"). w-1945) = 1,18 JPM₂ 12.82 1

(Base) (1) Blok & HU Ž Blont & H₂O .03 0.015 0015 0 0.013 pompkbi + log (Aud) = pich! poll, 2-1 : ona 794x10. so PH2 14-2.12 11-9 Ans (б) 2 (а и, ну – вси" 1,0 0.03 0.03 0 0 o oms 0.03 Bent Kh? 2. ton 0 asts x 003 0 03-X 0 X 1x2 mols, not 1 concentration) Khafa 00 - dla klubs flous) = x= 5000stylu 8 = 9 X 10'

I plonla-log (axl6") = 6-log 9 = 5.04 so PM, 14-5.04 = 8.95. Blomla thel - Bult rotho (in) 0.03 0 cous 8 .015 0 0.03 0 0.03 MUA Bout jebe i tanto ools 0 003 0.015 .. ools nts a buffes solution poll, pieb ilog And - 7.57 :.ph 14-7.54= 6.43 (v) moles of ht= 2x0.8 x 30 xlo 3 O , 10 x 10-3-0-06 Mile of on = 0.06 - Mcles of int = Molue of on sopl= 7