1. Chapter FifteenPrentice-Hall ©2002Slide 1 of 31 1 940701 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

2. Chapter FifteenPrentice-Hall ©2002Slide 2 of 31 940701 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides 2 Ionic equilibriums(2) (Mark=1)

3. Chapter FifteenPrentice-Hall ©2002Slide 3 of 31 Solubility products AgCl(s) ⇄ Ag + (aq) + Cl - (aq). 940701 3 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

4. Chapter FifteenPrentice-Hall ©2002Slide 4 of 31 940701 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides 4 Ionic equilibriums(2) (Mark=1)

5. Chapter FifteenPrentice-Hall ©2002Slide 5 of 31 Mg(OH) 2 (s)  Mg 2+ (aq) + 2OH - (aq) K sp = [Mg 2+ ][OH - ] 2 Ag 2 CrO 4 (s)  2Ag + (aq) + CrO 4 2- (aq) K sp = [Ag + ] 2 [CrO 4 2 - ] Solubility products 940701 5 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

6. Chapter FifteenPrentice-Hall ©2002Slide 6 of 31 Solubility or precipitation AgCl(s) ⇄ Ag + (aq) + Cl - (aq). Q sp =[Ag + ]×[Cl - ] – Q sp < K sp More solubility – Q sp = K sp Saturation – Q sp > K sp precipitation 940701 6 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

7. Chapter FifteenPrentice-Hall ©2002Slide 7 of 31 Solubility & Solubility products -x+x+2x PbF 2 (s)Pb 2+ (aq) + 2 F – (aq) K sp = [Pb 2+ ] [F – ] 2 = 3.7 x 10 –8 M 3 = (x) (2x) 2 = 3.7 x 10 –8 M 3 = 4x 3 = 3.7 x 10 –8 M 3 x = 2.1 x 10 –3 M 940701 7 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides K sp = [Pb 2+ ][F - ] 2

8. Chapter FifteenPrentice-Hall ©2002Slide 8 of 31 Solubility & Solubility products CaF 2 (s) ⇄ Ca +2 (aq) + 2F - (aq) K sp = 4.0 × 10 -11 x = 2.2 × 10 -4 M 0.017 g CaF 2 /liter. 940701 8 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides K sp = [Ca 2+ ][F - ] 2

9. Chapter FifteenPrentice-Hall ©2002Slide 9 of 31 Common ion effect & solubility 10 -10 1.3 10 -5 K sp =1.8 × 10 -10 x = 1.3 × 10 -5 Solubility of AgCl in H 2 O AgCl(s) ⇄ Ag+(aq) + Cl-(aq). 940701 9 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

10. Chapter FifteenPrentice-Hall ©2002Slide 10 of 31 Common ion effect & solubility 1.8 10 -9 1.3 10 -5.x = 1.8 × 10 -9 << 1.3 × 10 -5. Solubility of AgCl in NaCl(0.1M) AgCl(s) ⇄ Ag+(aq) + Cl-(aq). XX+0.1 940701 10 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

11. Chapter FifteenPrentice-Hall ©2002Slide 11 of 31 Common ion effect & solubility 1.8 10 -9 1.3 10 -5 H2Ox = 1.8 × 10 -9 0.1M NaCl<< 1.3 × 10 -5 H2O Solubility of AgCl in NaCl(  M) AgCl(s) ⇄ Ag+(aq) + Cl-(aq). Soluble [Ag(Cl) 2 ] - More Conc 940701 11 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

12. Chapter FifteenPrentice-Hall ©2002Slide 12 of 31 Salt effect & solubility Solubility of AgCl in NaNO 3 AgCl(s) ⇄ Ag+(aq) + Cl-(aq). AgCl(s) ⇄ Ag + + Cl - 940701 12 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

13. Chapter FifteenPrentice-Hall ©2002Slide 13 of 31 What Concentration of Ag+ is needed for precipitation of Ag 2 CrO 4 in 0.01M solution of CrO 4 2- ? Ag 2 CrO 4 (s)  2Ag + + CrO 4 2- K SP = [Ag + ] 2 [CrO 4 2- ] = 1.0 x 10 -12 [CrO 4 2- ] = 0.01 M [Ag + ] 2 = 1.0 x 10 -12 / 0.01 = 1.0 x 10 -10 [Ag + ] >1.0 x 10 -5 M 940701 13 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

14. Chapter FifteenPrentice-Hall ©2002Slide 14 of 31 Solubility & pH If Anion=weak base Cation=weak acid CaF 2  Ca 2+ +2F - AgCl  Cl - + Ag + H + HF OH - AgOH 940701 14 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

15. Chapter FifteenPrentice-Hall ©2002Slide 15 of 31 Solubility & pH What Conc. Of NH 4 + is necessary to prevent the formation of Mg(OH) 2 precipitate in a sol. of 0.050M in Mg 2+ & 0.050M in NH 3. K sp Mg(OH) 2 =8.9×10 -12, K b NH 3 =1.8×10 -5. [NH 4 ] + > 6.9 ×10 -2 M 940701 15 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

16. Chapter FifteenPrentice-Hall ©2002Slide 16 of 31 Precipitation of sulfides Pb 2+ +H 2 S  Pb(HS) 2  PbS (s) + H 2 S NiS (s)  Ni 2+ + S 2- K sp =3.0× 10 -21 PbS (s)  Pb 2+ + S 2- K sp =7.0× 10 -29 Pb 2+ + S 2-  PbS (s) H 2 S (s)  2H + + S 2- K sp =1.1× 10 -22 Fix constan t HCl 940701 16 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

17. Chapter FifteenPrentice-Hall ©2002Slide 17 of 31 Precipitation of sulfides What must be the H + Conc. Of a Sol. That is 0.10M in Ni 2+ to prevent the precipitation of NiS when the sol. is saturated with H 2 S. K sp NiS=1.0×10 -21 H 2 S (s)  2H + + S 2- K sp =1.0× 10 -22 [H + ] > 0.10 M 940701 17 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

18. Chapter FifteenPrentice-Hall ©2002Slide 18 of 31 Precipitation of sulfides A sol. That is 0.025M in Cd 2+ and 0.050M in H + is saturated with H 2 S.What Conc. Of Cd 2+ remains in sol. After CdS has precipitated. K sp CdS=1.0×10 -28. H 2 S (s)  2H + + S 2- K sp =1.0× 10 -22 [Cd 2+ ]= CdS=1.0×10 -8. 940701 18 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

19. Chapter FifteenPrentice-Hall ©2002Slide 19 of 31 Equilibria involving complex ions Ligand=complexor Coordination No. Chelate Zn 2+ + 6H 2 O [Zn(H2O) 6 ] 2+ K s =K f =1/K ins =1/K d 940701 19 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

20. Chapter FifteenPrentice-Hall ©2002Slide 20 of 31 Equilibria involving complex ions What is the Sol. Of AgCl in 0.1M NH 3 ? K sp AgCl=1.0×10 -10 K ins [Ag(NH 3 ) 2 ] + =1.0×10 -8 S=0.023 940701 20 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

21. Chapter FifteenPrentice-Hall ©2002Slide 21 of 31 940701 21 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

22. Chapter FifteenPrentice-Hall ©2002Slide 22 of 31 Equilibria involving complex ions A 0.010M Sol. Of AgNo 3 is made in 0.50M NH 3 and The complex [Ag(NH 3 ) 2 ] + forms. 1) What is the Conc. Of Ag + in the solution? 2) What percentage of total Conc. Of silver is in the form of Ag + ? 1)[Ag + ]=2.6×10 -9 2)2.6×10 -5 % 940701 22 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

23. Chapter FifteenPrentice-Hall ©2002Slide 23 of 31 Complex Ions with S 2- CuS + S 2-  ××× AS 2 S 3 + S 2-  2[AsS 3 ] 3- Al 3+ + …..NH 3  Al(OH) 3(s) Zn 2+ +…..NH 3  [Zn(NH 3 ) 4 ] 2+ 940701 23 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides

24. Chapter FifteenPrentice-Hall ©2002Slide 24 of 31 Amphoterism Mg 2+ +…..OH -  Mg(OH) 2(s) Zn 2+ + …...OH -  [Zn(OH) 4 ] 2- 940701 24 http:\\academicstaff.kmu.ac.ir\aliasadip our.....24 slides