Which of the following halides has the highest meting point ?

Options

A. NaCl
B. NaBr
C. NaF
D. Nal

Answer

To determine which of the following halides has the highest melting point among NaCl, NaBr, NaF, and NaI, we can follow these steps:

### Step 1: Understand the Compounds
We have four sodium halides to compare:
- NaCl (Sodium Chloride)
- NaBr (Sodium Bromide)
- NaF (Sodium Fluoride)
- NaI (Sodium Iodide)

### Step 2: Identify the Cation and Anion
In all these compounds, the cation is Na⁺ (Sodium ion), which remains constant. The anions are F⁻ (Fluoride), Cl⁻ (Chloride), Br⁻ (Bromide), and I⁻ (Iodide).

### Step 3: Consider Ionic Character
The melting point of ionic compounds is influenced by the ionic character, which is determined by the charge and size of the ions involved. The greater the charge and the smaller the size of the ions, the higher the melting point.

### Step 4: Compare the Anions
- **Fluoride (F⁻)**: Smallest size and highest electronegativity.
- **Chloride (Cl⁻)**: Larger than F⁻.
- **Bromide (Br⁻)**: Larger than Cl⁻.
- **Iodide (I⁻)**: Largest of all.

### Step 5: Analyze the Trends
Fluoride (F⁻) has the highest electronegativity and is the smallest ion, leading to a stronger ionic bond with Na⁺ compared to the other halides. As we move down the group from F to I, the size of the anion increases, which generally leads to a decrease in melting point due to weaker ionic bonds.

### Step 6: Conclusion
Based on the above analysis, NaF has the highest melting point due to its small size and high electronegativity, which results in a strong ionic bond.

### Final Answer
Thus, the halide with the highest melting point is **NaF**.

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