Acid-base titrations use indicators.  Transition range: pH range where color will change.

 

 

(Roughly translated: Only when all three tritration criteria are met can you do direct titrations)

 

 

 

 

Process where a species with one or more unshared electron pairs form a coordinate body with metal ions.

 

'Species'-->Ligands

 

Monodentate Ligand:  "One Tooth".  1 Unshared pair, 1 bond created.

                                          CN + Cd(2+)<-->(CdCN)+1

                                           Complexed are normally soluble.

 

Formation Constant (Kf): Very large, higher means tighter complex binding.  Multiple instances each have Kf (Get weaker as one adds more).

 

Beta=Kf1*Kf2*Kf3...                        Beta=[Cd(CN)42-]/[Cd2+][CN]^4

 

Cd2+ + CN- -->CdCN1+  Kf1

CdCn1+ + CN- -->Cd(CN)2  Kf2

Cd(CN)2 + CN- -->Cd(CN)3 Kf3

Cd(CN)3 + CN- -->Cd(CN)4 Kf4

 

Multidentate Ligands: Bond to single metal ion through more than one atom.

                     ex Ethylenediamine (EDA)

 

Chelate effect: Chelators form more stable complexes.

          Forms six bonds to metal ions.

Each protonated species has different Kf for each metal ion.

 

Must be basic to have a single species (Y4-).

 

 

 

Conditional formation Constant (Kf')

                     Set solution to certain pH

 

           Cd2+ + Y4- <-->(CdY)2-    Kf'=2.9x10^16

 

Roughly translated:  Use your brains for school, or let me eat them.  They're scrumptious.