The compound that has the higest ionic character associated with the X-Cl bond is :

Options

A. `PCl_(5)`
B. `BCl_(3)`
C. `C Cl_(4)`
D. `SiCl_(4)`

Explanation

To determine which compound has the highest ionic character associated with the X-Cl bond among PCl5, BCl3, CCl4, and SiCl4, we can follow these steps:

### Step 1: Understand Ionic Character
Ionic character in a bond is influenced by the electronegativity difference between the two atoms involved in the bond. The greater the difference, the higher the ionic character.

### Step 2: Identify the Common Anion
In this case, the common anion is Cl (chlorine) in all the compounds. Therefore, we need to focus on the cation (X) in each compound.

### Step 3: List the Cations
The cations in the given compounds are:
- P in PCl5
- B in BCl3
- C in CCl4
- Si in SiCl4

### Step 4: Compare the Cations
To determine which cation has the largest size, we can refer to their positions in the periodic table:
- Boron (B) and Carbon (C) are in the second period.
- Phosphorus (P) and Silicon (Si) are in the third period.

As we move down a group in the periodic table, the size of the atoms increases. Therefore, Si (Silicon) is larger than P (Phosphorus), and both B and C are smaller than Si and P.

### Step 5: Analyze the Ionic Character
According to Fajan's rules, for a bond to have a high ionic character, we need:
- A larger cation (which we have identified as Si).
- A smaller anion (Cl is common and remains the same).

Since Si is the largest cation among the options provided, the Si-Cl bond will exhibit the highest ionic character.

### Conclusion
Thus, the compound with the highest ionic character associated with the X-Cl bond is **SiCl4**.

### Final Answer
SiCl4 (Silicon tetrachloride) has the highest ionic character associated with the X-Cl bond.

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