Which of the following contains the maximum number of unpaired electrons?

Options

A. `TiCl_3`
B. `MnCl_3`
C. `FeSO_4`
D. `CuSO_4`

Answer

To determine which of the given compounds contains the maximum number of unpaired electrons, we will analyze each compound's oxidation state and electronic configuration.

### Step-by-Step Solution:

1. **Identify the Compounds and Their Oxidation States:**
- **TiCl3:** Titanium (Ti) has an oxidation state of +3.
- **MnCl3:** Manganese (Mn) has an oxidation state of +3.
- **Fe(CO)4:** Iron (Fe) has an oxidation state of +2.
- **CuSO4:** Copper (Cu) has an oxidation state of +2.

2. **Determine the Electronic Configurations:**
- **TiCl3:**
- Atomic number of Ti = 22.
- Electronic configuration of Ti = [Ar] 3d² 4s².
- For Ti in +3 oxidation state: 3d¹ (after losing 2 electrons from 4s and 1 from 3d).
- **MnCl3:**
- Atomic number of Mn = 25.
- Electronic configuration of Mn = [Ar] 3d⁵ 4s².
- For Mn in +3 oxidation state: 3d⁴ (after losing 2 electrons from 4s and 1 from 3d).
- **Fe(CO)4:**
- Atomic number of Fe = 26.
- Electronic configuration of Fe = [Ar] 3d⁶ 4s².
- For Fe in +2 oxidation state: 3d⁶ (after losing 2 electrons from 4s).
- **CuSO4:**
- Atomic number of Cu = 29.
- Electronic configuration of Cu = [Ar] 3d¹⁰ 4s¹.
- For Cu in +2 oxidation state: 3d⁹ (after losing 1 electron from 4s and 1 from 3d).

3. **Count the Unpaired Electrons:**
- **TiCl3 (3d¹):** 1 unpaired electron.
- **MnCl3 (3d⁴):** 4 unpaired electrons (the configuration is ↑↓ ↑ ↑ ↑).
- **Fe(CO)4 (3d⁶):** 4 unpaired electrons (the configuration is ↑↓ ↑ ↑ ↑ ↑).
- **CuSO4 (3d⁹):** 1 unpaired electron.

4. **Compare the Number of Unpaired Electrons:**
- TiCl3: 1 unpaired electron.
- MnCl3: 4 unpaired electrons.
- Fe(CO)4: 4 unpaired electrons.
- CuSO4: 1 unpaired electron.

5. **Conclusion:**
- Both MnCl3 and Fe(CO)4 have the maximum number of unpaired electrons, which is 4.

### Final Answer:
**MnCl3 and Fe(CO)4 contain the maximum number of unpaired electrons (4 each).**