Among the following the electron deficient compound is

Options

A. `BCl_(3)`
B. `"CCl"_(4)`
C. `PCl_(5)`
D. `BeCl_(2)`

Explanation

To determine which of the given compounds is electron deficient, we will analyze each compound based on its electron configuration and bonding.

### Step-by-Step Solution:

1. **Understanding Electron Deficiency**:
- An electron deficient compound is characterized by having an incomplete octet, meaning it has fewer than eight electrons in its valence shell.

2. **Analyzing Each Compound**:
- **Boron Trichloride (BCl3)**:
- Boron has an atomic number of 5, with an electronic configuration of 2, 3.
- It has three valence electrons and forms three bonds with chlorine atoms.
- Each chlorine atom contributes one electron, leading to a total of 6 electrons around boron (3 from boron and 3 from chlorine).
- Since boron has only 6 electrons, it is electron deficient.

- **Carbon Tetrachloride (CCl4)**:
- Carbon has four valence electrons and forms four bonds with chlorine atoms.
- Each chlorine atom contributes one electron, resulting in a complete octet (4 from carbon and 4 from chlorine).
- Therefore, CCl4 is not electron deficient.

- **Phosphorus Pentachloride (PCl5)**:
- Phosphorus has five valence electrons and forms five bonds with chlorine atoms.
- Each chlorine atom contributes one electron, resulting in a complete octet (5 from phosphorus and 5 from chlorine).
- Thus, PCl5 is not electron deficient.

- **Beryllium Dichloride (BeCl2)**:
- Beryllium has two valence electrons and forms two bonds with chlorine atoms.
- Each chlorine atom contributes one electron, leading to a total of 4 electrons around beryllium (2 from beryllium and 2 from chlorine).
- Beryllium typically does not complete an octet and is considered electron deficient.

3. **Conclusion**:
- Among the compounds analyzed, both BCl3 and BeCl2 are electron deficient. However, BCl3 is the classic example of an electron deficient compound due to its incomplete octet with only 6 electrons.

### Final Answer:
The electron deficient compound among the options is **Boron Trichloride (BCl3)**.

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