Question

12. (4 pts) Show the chemical equations for what happens when a) H30" and b) OH are added to a HNO2 NaNO2 buffer t b. Offt Na NO,Natt tN 13. (4 pts) Below is a titration curve for titrating a weak acid with NaOH. Show on the graph by drawing how the pKa can be determined. What is the pK,? PKa-109 Ka PKat 109 CND 2244 4-0 kn 109 ka PtH-PKa 109 se 150 20 volume NadHaaded (m) 14. (6 pts) Assume you have a 9.0 L of a buffer which is 0.15 M propionic acid and 0.085 M sodium propionate. What is the pH of the buffer after you have added 0.0525 moles of NaOH? The pKs of propionic acid is 4.88. [0g5 085.0525 [13]s) CiS Ptt 1.80 109 rtt 4.63

Answer 1

a When Ho s added Na t0 Na No e bWhen ore is added ने ह० HNO,+OHe Noe t hal equitalenes foint ph pka. half equiale pain Hence V.SomL A nd uhem V3 seml pka ph: 4.8 ph pkas lagediun Phopionak) CPrupanaic aud) + t8 O Wha b.0.525 mel of NaOr addes CH Ch COOM +O,e of + O.IS O.6s25 inihal +0.0525 -0.052r chomge Equlibrium 0.15-00525 -0.0525 0.025+0.a5er O.137s ml CA0.0915Mo) JHemce egm Can o propimic ceid 0.09 75 m m Phopionate O-131 m M this in es D Put 4.884 log 0-131 O-0175 4.88+ 0-14 S. 03 Hd PH