Question
Write note on oxides and oxoanions of 3d transition metals.
✓
Answer
→ The ability of oxygen to stabilize the high oxidation states of metal than fluorine is higher because it forms a multiple bonds with a metal.
→ The metal oxide in lower oxidation state is basic while in higher oxidation state are acidic.
→ The metal oxides having metals in intermediate oxidation states are amphoteric.
e.g.
Oxides of 3d Metals
* mixed oxides
→ In the covalent oxide $Mn _2 O _7$, each Mn is tetrahedrally surrounded by O 's including a $Mn - O - Mn$ bridge. The tetrahedral $\left[ MO _4\right]^{ n -}$ ions are known for $V ^{ V }, Cr ^{ VI }, Mn ^{ V }, Mn ^{ VI }$ and $Mn ^{ VII }$.
→ The metal oxide in lower oxidation state is basic while in higher oxidation state are acidic.
→ The metal oxides having metals in intermediate oxidation states are amphoteric.
e.g.
| Acidic oxide | Basic oxide | Amphoteric oxide |
| $Mn _2 O _7$ | MnO | $Mn _3 O _4, Mn _2 O _3, MnO _2$ |
| CrO | $Cr _2 O _3$ |
| Oxidati on NUmber | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| +7 | $Mn _2 O _7$ | |||||||||
| +6 | $CrO _3$ | |||||||||
| +5 | $V _2 O _5$ | |||||||||
| +4 | $TiO _2$ | $V _2 O _4$ | $CrO _2$ | $MnO _2$ | ||||||
| +3 | $Sc _2 O _3$ | $Ti _2 O _3$ | $V _2 O _3$ | $Cr _2 O _3$ | $\begin{array}{l} Mn _2 O _3 \\ Mn _3 O _4^*\end{array}$ | $\begin{array}{l} Fe _2 O _3 \\ Fe _3 O _4^*\end{array}$ | $Co _3 O _4{ }^*$ | |||
| +2 | TiO | VO | (CrO) | MnO | FeO | CoO | NiO | CuO | ZnO | |
| +1 | $Cu _2 O$ |
→ In the covalent oxide $Mn _2 O _7$, each Mn is tetrahedrally surrounded by O 's including a $Mn - O - Mn$ bridge. The tetrahedral $\left[ MO _4\right]^{ n -}$ ions are known for $V ^{ V }, Cr ^{ VI }, Mn ^{ V }, Mn ^{ VI }$ and $Mn ^{ VII }$.
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