What is correct statement ?

Options

A. Iodides of alkali metals have highest ionic character among halides
B. LiF is highly soluble in `H_2O`
C. Low solubility of Csl is due to smaller hydration enthalpy of its two ions
D. All of these

Answer

To determine the correct statement among the given options, we will analyze each statement step by step.

### Step 1: Analyze the First Statement
**Statement:** Iodides of alkali metals have the highest ionic character among halides.

- **Explanation:** Alkali metals include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Iodine (I) is a halogen. The iodides formed by alkali metals (e.g., LiI, NaI, KI) have a high ionic character due to the large size of the iodide ion (I⁻). The large size results in a low effective nuclear charge on the outermost electrons, making them easier to remove and thus forming strong ionic bonds. Therefore, this statement is **correct**.

### Step 2: Analyze the Second Statement
**Statement:** Lithium fluoride is highly soluble in water.

- **Explanation:** Lithium fluoride (LiF) has a significant ionic character but also exhibits partial covalent character due to the small size of both Li⁺ and F⁻ ions. It has high lattice energy, which is the energy required to separate the ions in the solid state. Additionally, it has low hydration energy because the small size of the ions means fewer water molecules can surround them effectively. Due to the high lattice energy and low hydration energy, lithium fluoride is not highly soluble in water. Therefore, this statement is **incorrect**.

### Step 3: Analyze the Third Statement
**Statement:** Low solubility of cesium iodide is due to the smaller hydration enthalpy of its two ions.

- **Explanation:** Cesium iodide (CsI) dissociates into Cs⁺ and I⁻ ions. The Cs⁺ ion has a large size, leading to lower hydration energy compared to smaller ions. Lower hydration energy means that the energy released when water molecules surround the ions is not sufficient to overcome the lattice energy of CsI. Thus, CsI is less soluble in water. Therefore, this statement is **correct**.

### Step 4: Analyze the Fourth Statement
**Statement:** All of these.

- **Explanation:** Since the second statement is incorrect, the statement "All of these" cannot be true. Therefore, this statement is **incorrect**.

### Conclusion
- The correct statements are the first and third ones. The second statement is incorrect, and thus the fourth statement cannot be correct.

### Final Answer
The correct statements are:
1. Iodides of alkali metals have the highest ionic character among halides.
2. Low solubility of cesium iodide is due to the smaller hydration enthalpy of its two ions.