Q. Llimitations of werners theory?

There were inherent limitations with such a simple approach. For example, the following experimental facts cannot be explained on the basis of such a simple model:

• certain metal ions show stronger tendency to form complexes compared to others;
• certain elements can form complexes with different coordination numbers as well as in different oxidation states;
• Some metal ion complexes are very reactive and exchange ligands in typical substitution of reactions whereas others do not.
• a particular geometrical shape appears to be preferred by some ions;
• Most of the transition element complexes show typical sharp colours.