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Chap 16 Part 4Ta.notebook January 30, 2018
Complex Ions and Simultaneous Equilibria
Complex Iona charged aqueous species consisting of a metal ion surrounded by ligands
Examples of ligandsH2O, NH3, Cl, CN
Ligands all have lone pairs that are attracted to the positive metal, the number of ligands is call the coordination number
Co(H2O)62+Ni(NH3)62+CoCl42Cu(NH3)42+Ag(NH3)2+
Complex Ions often form colorful solutions with transition metals!
http://www.youtube.com/watch?v=mI1K4Hpjr0U
Chap 16 Part 4Ta.notebook January 30, 2018
Complex Ions and Solubility
AgCl (s) Ag+(aq) + Cl (aq)
Ksp = 1.6 x 1010
How to shift the eq. to the right?
Remove a product!
Ag+ + NH3 Ag(NH3)+ K = 2100
Ag(NH3)+ + NH3 Ag(NH3)2+ K = 8200
Solubility of AgCl in pure water is 1.3 x 105 mol/L
Solubility of AgCl in 10.0 M NH3 is 0.48 mol/L
Take Home Message• Dissolving a solid in a solution with a common ion REDUCES solubility• Dissolving a solid in a solution that can form a complex ion with the cation INCREASES solubility
Reason is the same Le Chatelier's Principle!
Chap 16 Part 4Ta.notebook January 30, 2018
Simultaneous equilibriatwo or more reactions that occur at the same time in a solution
PbCl2 Ksp = 1.7 x 105PbCrO4 Ksp = 1.8 x 1014
A few drops of K2CrO4 is added to a small amount of white precipitate of PbCl2. Find K of the reaction.
PbCl2 + CrO4 2 PbCrO4 + 2 Cl
The compound with the lower solubility will form the precipitate.
Chap 16 Part 4Ta.notebook January 30, 2018
Can silver chloride be converted to silver bromide by adding bromide ion?
AgCl(s) + Br (aq) AgBr (s) + Cl (aq)
AgCl Ksp = 1.6 x 1010AgBr Ksp = 5.0 x 1013
Chap 16 Part 4Ta.notebook January 30, 2018