The manganate and permanganate ions are tetrahedral, due to:
| 1. | The π-bonding involves the overlap of d-orbitals of oxygen with d-orbitals of manganese. |
| 2. | The π-bonding involves the overlap of p-orbitals of oxygen with d-orbitals of manganese. |
| 3. | Absence of π-bonding. |
| 4. | The π-bonding involves the overlap of p-orbitals of oxygen with p-orbitals of manganese. |
In acidic medium, H2O2 changes Cr2O7–2 to CrO5 which has two (–O – O–) bonds.
The oxidation state of Cr in CrO5 is:
1. +5
2. +3
3. +6
4. -10