Which one is the highest melting halide ?

Options

A. NaCl
B. LiCl
C. LiBr
D. NaI

Answer

To determine which halide has the highest melting point, we can analyze the properties of the halides formed by sodium (Na) and lithium (Li). Here’s a step-by-step breakdown of the reasoning:

### Step 1: Identify the Halides
The halides we are considering are:
- Lithium halides: LiCl and LiBr
- Sodium halides: NaCl and NaBr

### Step 2: Understand Covalent Character
The melting points of ionic compounds are influenced by their ionic or covalent character. Generally, the more covalent a compound is, the lower its melting point.

### Step 3: Analyze the Covalent Character
- **Lithium Halides**:
- LiCl and LiBr are covalent in nature due to the small size of the lithium cation (Li⁺) and the larger size of the anions (Cl⁻ and Br⁻).
- Smaller cations and larger anions lead to a higher covalent character.

- **Sodium Halides**:
- NaCl and NaBr are more ionic compared to the lithium halides.
- Sodium (Na⁺) is larger than lithium (Li⁺), which reduces the covalent character.

### Step 4: Compare Melting Points
- **LiCl and LiBr**: These will have lower melting points due to their covalent nature.
- **NaCl and NaBr**: Among these, NaCl will have a higher melting point than NaBr because:
- NaCl has a smaller anion (Cl⁻) compared to NaBr (Br⁻), which means NaCl has a lower covalent character.

### Step 5: Conclusion
Based on the analysis, NaCl has the highest melting point among the halides considered. Therefore, the answer to the question is:
**NaCl is the highest melting halide.**

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