Question

The most basic oxide among MnO,Mn₂​O₃​,MnO₂​ and Mn₂​O₇​ is :

Answer 1

In MnO, Mn has oxidation state of +2 and is least acidic or most basic and Mn₂​O₇​ has Mn in +7 oxidation state so it is most acidic and least basic. The basicity decreases with increasing oxidation state.

Answer 2

Molecular weight of MNO₂, MnO₃, MnO₃ and Mn₂O₇ are 87 g/mol, 158 g/mol, 103 g/mol and 222 g/mol.

% of combined oxygen in MnO₂ = \(\frac{32}{87}\times100\) = 36.8 %

% of combined oxygen in Mn₂O₃ = \(\frac{48}{158}\times100\) = 31%

% of combined oxygen in MnO₃ = \(\frac{48}{103}\times100\) = 46.6%

% of combined oxygen in Mn₂O₂ = \(\frac{112}{222}\times100\) = 50.4%

Thus, Mn₂O₇ has maximum percentage of combined oxygen by weight i.e.,= 50.4%