Which one of the following is highest melting point

Options

A. AgCl
B. AgBr
C. AgF
D. AgI

Explanation

To determine which of the given compounds has the highest melting point, we will analyze the compounds based on their ionic character and the size of their anions.

### Step 1: Identify the Compounds
The compounds we are comparing are:
1. Silver Chloride (AgCl)
2. Silver Bromide (AgBr)
3. Silver Fluoride (AgF)
4. Silver Iodide (AgI)

### Step 2: Understand Fajan's Rule
According to Fajan's rule, the polarization of an anion by a cation is influenced by the size of the anion and the charge density of the cation. Smaller anions are less polarizable than larger anions. This means that the smaller the anion, the more ionic the compound tends to be, leading to a higher melting point.

### Step 3: Compare the Sizes of the Anions
- Fluoride (F⁻) is the smallest anion.
- Chloride (Cl⁻) is larger than fluoride.
- Bromide (Br⁻) is larger than chloride.
- Iodide (I⁻) is the largest anion among these.

### Step 4: Analyze Ionic Character
Since AgF has the smallest anion (F⁻), it will be the most ionic and, therefore, expected to have the highest melting point. The order of ionic character based on the size of the anions is:
- AgF > AgCl > AgBr > AgI

### Step 5: Conclusion
Based on the analysis, Silver Fluoride (AgF) has the highest melting point among the given compounds.

### Final Answer
**Silver Fluoride (AgF) has the highest melting point.**

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