Formation of oxides of d-block elements

Formation of oxides of d-block elements

Transition metals form oxides on reaction with oxygen at elevated temperature. Transition metal form oxide in oxidation state of + 1 (in Ag₂O) to + 7 (Mn₂O₇) to + 8 (in OsO₄). As the oxidation number increases in case of same elements:

• The covalent character of oxides increases.
• The acidic strength of the oxides increases.
• The oxidizing power of oxides increases.

For example, Cr₂O₃ is amphoteric while CrO is basic and CrO₃ is acidic.