Mention the main postulates of Werner’s Theory.
The main postulates of Werner’s Theory are: (i) Two types of valencies are shown by the central metal ion, the primary and the secondary valency. (ii) The oxidation state of the compound is its primary valency and the coordination number of a complex is its secondary valency. (iii) The secondary valency for every species is fixed, it means that the coordination number is fixed. (iv) The primary and secondary valencies of a metal atom are both satisfied by the metal atom. The main valency is satisfied by a negative ion. Negative ions and neutral molecules, on the other hand, fulfil secondary valencies.
