Question

The basic character of the transition metal monoxide follows the order

• A. $ VO>CrO>TiO>FeO $
• B. $ CrO>VO>FeO>TiO $
• C. $ TiO>FeO>VO>CrO $
• D. $ TiO>VO>CrO>FeO $

Answer 1

The Correct Option is D

Larger the size of a cation, lesser is its polarising power. A cation with lesser polarising power means lesser covalent character or more ionic character of its compound. A metal oxide with more ionic character will be more basic. The correct order of $M^{2+}$ ionic radii is as follows $Ti ^{2+}> V ^{2+}> Cr ^{2+}> Fe ^{2+}$ Ionic character of oxides in decreasing order, is as follows $TiO > VO > CrO > FeO$ This is also the order of basic character.