Which of the following is an electron deficient compound?

Options

A. `MgCl_(2)`
B. `BCl_(3)`
C. `GeCl_(3)`
D. `C Cl_(4)`

Explanation

To determine which of the given compounds is an electron-deficient compound, we need to analyze the electron configuration and the number of valence electrons around the central atom of each compound.

### Step-by-Step Solution:

1. **Identify the Compounds**: The options provided are:
- Option 1: MgCl2 (Magnesium Chloride)
- Option 2: BCl3 (Boron Trichloride)
- Option 3: GeCl3 (Germanium Trichloride)
- Option 4: CCl4 (Carbon Tetrachloride)

2. **Understand Electron Deficiency**: An electron-deficient compound is one that does not have a complete octet around its central atom. Typically, this means that the central atom has fewer than 8 electrons in its valence shell.

3. **Analyze Each Compound**:
- **MgCl2**: Magnesium has 2 valence electrons and forms ionic bonds with chlorine. The magnesium atom donates its 2 electrons to 2 chlorine atoms, resulting in a complete octet for chlorine but not for magnesium. However, magnesium is not considered electron-deficient in the same way that covalent compounds are.

- **BCl3**: Boron has 3 valence electrons and forms covalent bonds with 3 chlorine atoms. In BCl3, boron shares its 3 electrons with 3 chlorine atoms, resulting in only 6 electrons around boron. Therefore, BCl3 is electron-deficient because boron does not achieve a complete octet.

- **GeCl3**: Germanium has 4 valence electrons and forms covalent bonds with 3 chlorine atoms. In GeCl3, germanium shares its 4 electrons with 3 chlorine atoms, resulting in 7 electrons around germanium. While it is not a complete octet, it is not typically classified as electron-deficient in the same way as BCl3.

- **CCl4**: Carbon has 4 valence electrons and forms covalent bonds with 4 chlorine atoms. In CCl4, carbon shares its 4 electrons with 4 chlorine atoms, resulting in a complete octet (8 electrons) around carbon.

4. **Conclusion**: Among the given compounds, BCl3 is the only one that is electron-deficient because it has only 6 electrons around the boron atom.

### Final Answer:
The electron-deficient compound is **BCl3 (Option 2)**.