Oxidation number of Cr in `CrO_(5)` is

Options

A. `+10`
B. `+6`
C. `+4`
D. `+5`

Answer

To determine the oxidation number of chromium (Cr) in CrO₅, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the oxidation states of oxygen**:
- In most compounds, oxygen has an oxidation state of -2. However, in peroxides, it has an oxidation state of -1.

2. **Determine the structure of CrO₅**:
- CrO₅ contains 4 oxygen atoms in the form of peroxides and 1 oxygen atom in a double bond. This means we have:
- 4 oxygen atoms contributing -1 each (from the peroxide linkages).
- 1 oxygen atom contributing -2 (from the double bond).

3. **Calculate the total oxidation state of oxygen**:
- The total contribution from the 4 peroxide oxygens is:
\[ 4 \times (-1) = -4 \]
- The contribution from the 1 double-bonded oxygen is:
\[ 1 \times (-2) = -2 \]
- Therefore, the total oxidation state from all the oxygen atoms in CrO₅ is:
\[ -4 + (-2) = -6 \]

4. **Set up the equation for the oxidation state of chromium**:
- Let the oxidation state of chromium be \( x \).
- The sum of the oxidation states in a neutral compound must equal zero. Thus, we can write the equation:
\[ x + (-6) = 0 \]

5. **Solve for \( x \)**:
- Rearranging the equation gives:
\[ x = +6 \]

6. **Conclusion**:
- The oxidation number of chromium in CrO₅ is +6.