Valence of the metal atom with respect to oxygen is maximum in

Options

A. `Mn_2O_7`
B. `OsO_4`
C. `MnO_2`
D. `CrO_3`

Explanation

To determine the maximum valence of the metal atom with respect to oxygen from the given compounds, we will analyze each compound step by step.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds we need to analyze are Mn2O7, OsO4, MnO2, and CrO3.

2. **Calculate the Oxidation State of Manganese in Mn2O7**:
- The formula is Mn2O7.
- Oxygen (O) has an oxidation state of -2.
- There are 7 oxygen atoms, contributing a total of \(7 \times -2 = -14\).
- Let the oxidation state of manganese (Mn) be \(x\).
- The equation is:
\[ 2x + (-14) = 0 \implies 2x = 14 \implies x = +7 \]
- Therefore, the oxidation state of Mn in Mn2O7 is +7.

3. **Calculate the Oxidation State of Osmium in OsO4**:
- The formula is OsO4.
- Oxygen has an oxidation state of -2.
- There are 4 oxygen atoms, contributing a total of \(4 \times -2 = -8\).
- Let the oxidation state of osmium (Os) be \(y\).
- The equation is:
\[ y + (-8) = 0 \implies y = +8 \]
- Therefore, the oxidation state of Os in OsO4 is +8.

4. **Calculate the Oxidation State of Manganese in MnO2**:
- The formula is MnO2.
- Oxygen has an oxidation state of -2.
- There are 2 oxygen atoms, contributing a total of \(2 \times -2 = -4\).
- Let the oxidation state of manganese (Mn) be \(z\).
- The equation is:
\[ z + (-4) = 0 \implies z = +4 \]
- Therefore, the oxidation state of Mn in MnO2 is +4.

5. **Calculate the Oxidation State of Chromium in CrO3**:
- The formula is CrO3.
- Oxygen has an oxidation state of -2.
- There are 3 oxygen atoms, contributing a total of \(3 \times -2 = -6\).
- Let the oxidation state of chromium (Cr) be \(w\).
- The equation is:
\[ w + (-6) = 0 \implies w = +6 \]
- Therefore, the oxidation state of Cr in CrO3 is +6.

6. **Compare the Oxidation States**:
- From the calculations:
- Mn in Mn2O7: +7
- Os in OsO4: +8
- Mn in MnO2: +4
- Cr in CrO3: +6
- The maximum oxidation state is +8, which corresponds to osmium in OsO4.

### Conclusion:
The valence of the metal atom with respect to oxygen is maximum in OsO4, where osmium has an oxidation state of +8.