In: Chemistry
1.What is the coordination number for each of the following complexes?
[Co(NH3)4Cl2]+
[Pb(EDTA)]2?
[Cu(NH3)4]2+
[Ag(NH3)2]NO3
2.What is the charge on each of the following complex ions?
hexaaquachromium(II), [Cr(H2O)6]?
tris(carbonato)ferrate(III), [Fe(CO3)3]?
diaquatetrabromovanadate(III), [V(H2O)2Br4]?
3.What is the oxidation number of the central metal ion in each of the following complexes?
[NiCl2Br2]2?
[Fe(H2O)2(NH3)4]3+
Na[Rh(CN)2]
(1) NH3 , Cl- are mono dentate ligands & EDTA is a hexadentate ligand
To know the coordination number of a metal ion we have to identify the number of ligands present around the central metal in the complex that is which are in the square brakets.
[Co(NH3)4Cl2]+ --- Here 4 NH3 & 2 Cl- are present , a total of 4+2 = 6 is the coordination number
[Pb(EDTA)]2+ --- Here 1 EDTA is presentwhich is a hexadentate ligand so 6 is the coordination number
[Cu(NH3)4]2+ --- Here 4 NH3 are present , a total of 4 is the coordination number
[Ag(NH3)2]NO3 --- Here 2 NH3 , 2 is the coordination number
(2)H2O --- neutral ligand : CO32- ----- bidantate ligand : Br- ---- monodentate ligand
hexaaquachromium(II), [Cr(H2O)6]?
since the oxidation state of Cr is II & H2O is a neutral ligand, the charge of the complex becomes +2+(6x0)= +2
Since the oxidation states of the complex is equal to the oxidation state of the metal ions & the ligands.
tris(carbonato)ferrate(III), [Fe(CO3)3]?
since the oxidation state of Fe is III & CO32- is a bidantate ligand , the charge of the complex becomes +3+(3x(-2))= -3
diaquatetrabromovanadate(III), [V(H2O)2Br4]?
since the oxidation state of V is III & H2O is a neutral ligand& Br- is a monodantate ligand , the charge of the complex becomes +3+(2x0)+(4x(-1)) = -1
(3)The sum of the oxidation state of the metal ion & the ligands present in the complex is equal to the charge on that complex.
Let a be the oxidation state of metal in each complex
[NiCl2Br2]2- Cl- & Br- are monodentate ligands
x +(2x(-1))+(2x(-1))= -2
x = +2
[Fe(H2O)2(NH3)4]3+ H2O & NH3 are neutral ligands
x +(2x0)+(4x0)= +3
x = +3
Na[Rh(CN)2] CN- is a monodentate ligand
The oxidation sate of Na is +1
+1 +[x +(2x(-1))]= 0
x = +1