Discuss the main postulates of Werner’s coordination theory.

Explanation

The main postulates of Wernen.s theory are :
(i) In co-ordination compounds, metals show two types of linkages (valences)-primary and secondary
(ii) The primary valences are normally ionisable and are satisfied by negative ions.
(iii) The secondary valences are non-ionisable. They are satisfied by, neutral molecules or negative ions. The secondary valence is equal to the co-ordination number and is fixed for a metal.
(iv). The `"ions"//"groups"` bound by the secondary linkages to the metal have characteristic spatial arrangements corresponding to different co-ordination numbers.