In chromyl chloride, the number of d-electrons present on chromium is same as in (Given at no. at Ti: 22, V: 23, Cr: 24, Mn: 25, Fe: 26)

Options

A. `Fe(III)`
B. `Mn(VII)`
C. `Ti(III)`
D. `V(IV)`

Answer

To solve the question, we need to determine the number of d-electrons present in chromium when it is in chromyl chloride (CrO2Cl2) and then compare it with the d-electrons in other transition metals.

### Step-by-Step Solution:

1. **Identify the Compound**:
The compound in question is chromyl chloride, which has the formula CrO2Cl2.

2. **Determine the Oxidation State of Chromium**:
To find the oxidation state of chromium (Cr) in CrO2Cl2, we can use the following equation:
\[ \text{Oxidation state of Cr} + 2(\text{Oxidation state of O}) + 2(\text{Oxidation state of Cl}) = 0 \]
The oxidation states are:
- Oxygen (O) = -2
- Chlorine (Cl) = -1

Plugging in the values:
\[ X + 2(-2) + 2(-1) = 0 \]
\[ X - 4 - 2 = 0 \]
\[ X - 6 = 0 \implies X = +6 \]
Therefore, the oxidation state of chromium in chromyl chloride is +6.

3. **Write the Electronic Configuration of Chromium**:
The atomic number of chromium (Cr) is 24. Its ground state electronic configuration is:
\[ \text{Cr: } [Ar] 3d^5 4s^1 \]

4. **Determine the Electron Configuration in +6 Oxidation State**:
When chromium is in the +6 oxidation state, it loses 6 electrons. The electrons are removed first from the 4s orbital and then from the 3d orbital:
\[ \text{Cr}^{+6}: 3d^0 4s^0 \]
Thus, in the +6 oxidation state, chromium has 0 d-electrons.

5. **Compare with Other Elements**:
Now we need to compare the number of d-electrons in chromium (+6 state) with the d-electrons in other transition metals:
- Titanium (Ti): Atomic number 22, configuration: 3d^2 4s^2 → +3 state: 3d^1 (1 d-electron)
- Vanadium (V): Atomic number 23, configuration: 3d^3 4s^2 → +4 state: 3d^1 (1 d-electron)
- Chromium (Cr): Atomic number 24, configuration: 3d^5 4s^1 → +6 state: 3d^0 (0 d-electrons)
- Manganese (Mn): Atomic number 25, configuration: 3d^5 4s^2 → +7 state: 3d^0 (0 d-electrons)
- Iron (Fe): Atomic number 26, configuration: 3d^6 4s^2 → +3 state: 3d^5 (5 d-electrons)

6. **Conclusion**:
The number of d-electrons in chromium in chromyl chloride (0 d-electrons) is the same as in manganese in the +7 oxidation state (0 d-electrons).

### Final Answer:
The number of d-electrons present on chromium in chromyl chloride is the same as in manganese in the +7 oxidation state.