The alkali metal halide that is soluble in pyridine is

Options

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

Explanation

To determine which alkali metal halide is soluble in pyridine, we can follow these steps:

### Step 1: Understand the nature of pyridine
Pyridine is an organic solvent that is covalent in nature. This means it is more likely to dissolve covalent compounds rather than ionic ones.

**Hint:** Remember that "like dissolves like" - covalent solvents dissolve covalent compounds.

### Step 2: Analyze the alkali metal halides
The options given are:
1. NaCl (Sodium Chloride)
2. LiCl (Lithium Chloride)
3. KCl (Potassium Chloride)
4. CsI (Cesium Iodide)

All of these compounds are ionic in nature, but we need to identify which one has covalent characteristics.

**Hint:** Check the size and charge density of the alkali metal ions in the halides.

### Step 3: Identify the covalent character in LiCl
Among the given options, LiCl is known to exhibit some covalent character. This is due to the small size of the lithium ion (Li⁺) which leads to a high charge density. The high charge density causes polarization of the chloride ion (Cl⁻), making the bond between them more covalent.

**Hint:** Small ions with high charge density can lead to covalent character in ionic compounds.

### Step 4: Conclusion
Since pyridine is a covalent solvent, it will dissolve covalent compounds. Therefore, the alkali metal halide that is soluble in pyridine is **LiCl (Lithium Chloride)**.

**Final Answer:** LiCl