On the basis of the following observations made with aqueous solutions, assign primary and secondary valencies to metals in the following compounds:
Formula |
Motes of AgCl precipitated with excess AgNO3 |
(i) PdCl2.4NH3 |
2 |
(ii) NiCl2.6H2O |
2 |
(iii) PtCl4.2HCl |
0 |
(iv) CoCl3.4NH3 |
1 |
(v) PtCl2.2NH3 |
0 |
.
The coordination number of a metal ion in a complex can be defined as the number of ligand donor atoms to which the metal is directly bonded.
The coordination number for a metal atom or ion is equal to the number of ligands attached to it. In case of monodendate ligands it attached by one donor atom and it is double in case of didentate ligands. Sometimes the sigma bond between the metal atom is represented by two dots before the donor atom, e.g., [Co(: (NH3)6)3+, [Ni(: CO)4].