Which of the following chloride has considerable covalent character ?

Options

A. LiCl
B. NaCl
C. KCl
D. CsCl.

Explanation

To determine which chloride has considerable covalent character, we can apply Fajans' rule. This rule helps us understand the extent of covalent character in ionic compounds based on the polarization of anions by cations. Let's break down the solution step by step:

### Step-by-Step Solution:

1. **Understand Fajans' Rule**:
Fajans' rule states that the covalent character of an ionic compound increases when the cation is small and highly charged, and the anion is large and easily polarizable.

2. **Identify the Cations**:
The question involves chlorides of lithium (Li), sodium (Na), potassium (K), and cesium (Cs). The cations are:
- Li⁺
- Na⁺
- K⁺
- Cs⁺

3. **Compare Cation Sizes**:
The size of cations increases as we move down the group in the periodic table. Therefore:
- Li⁺ is the smallest cation.
- Na⁺ is larger than Li⁺.
- K⁺ is larger than Na⁺.
- Cs⁺ is the largest cation.

4. **Identify the Anions**:
The anion in all cases is Cl⁻, which is the same for all options. Therefore, we only need to focus on the cation size.

5. **Apply Fajans' Rule**:
According to Fajans' rule, a smaller cation (like Li⁺) will polarize the larger anion (like Cl⁻) more effectively than larger cations. Thus, Li⁺ will have a greater covalent character in LiCl compared to NaCl, KCl, or CsCl.

6. **Conclusion**:
Based on the analysis, LiCl (lithium chloride) has considerable covalent character due to the small size of the Li⁺ cation, which leads to significant polarization of the Cl⁻ anion.

### Final Answer:
**LiCl has considerable covalent character.**