Write any two postulates of Werner's theory of co-ordination compounds.

Explanation

Postulates of Werner.s theory :
1. The central metal ion of complex compound has two types of valency namely primary and secondary valency.
2. Primary valency is ionisable while secondary valency is non - ionisable.
3. Primary valency corresponds to oxidation state and secondary valency correspond to co - ordination number of central metal ion.