Which of the following is the most ionic ? .

Options

A. `P_(4)O_(10)`
B. `MnO`
C. `CrO_(3)`
D. `Mn_(2)O_(7)`

Explanation

To determine which of the given compounds is the most ionic, we will follow these steps:

### Step 1: Identify the Compounds
We are given four oxides, and we need to analyze their cations to determine which one has the most ionic character. The compounds are:
1. B4O10
2. MnO
3. CrO3
4. Mn2O7

### Step 2: Determine the Oxidation States of the Cations
Next, we will find the oxidation states of the cations in each compound:
- In B4O10, the oxidation state of B (Boron) is +5.
- In MnO, the oxidation state of Mn (Manganese) is +2.
- In CrO3, the oxidation state of Cr (Chromium) is +6.
- In Mn2O7, the oxidation state of Mn is +7.

### Step 3: Analyze the Polarizing Power
According to Fajan's rule, the polarizing power of a cation is directly proportional to its charge and inversely proportional to its size. Higher charge and smaller size lead to greater polarizing power, which in turn leads to more covalent character and less ionic character.

### Step 4: Compare the Cations
Now, we will compare the cations based on their charges:
- B4O10: +5 (Boron)
- MnO: +2 (Manganese)
- CrO3: +6 (Chromium)
- Mn2O7: +7 (Manganese)

### Step 5: Determine Ionic Character
From the analysis:
- The cation with the highest charge (+7 in Mn2O7) will have the most polarizing power and thus the least ionic character.
- The cation with the lowest charge (+2 in MnO) will have the least polarizing power and thus the most ionic character.

### Conclusion
Based on the above analysis, MnO, with the +2 oxidation state, has the most ionic character among the given compounds.

### Final Answer
**MnO is the most ionic compound.**

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