Strongest acidic oxide among these is

Options

A. `Al_2 O_3 `
B. MgO
C. `Na_2O `
D. CaO

Answer

To determine the strongest acidic oxide among the given options (Al₂O₃, MgO, Na₂O, and CO), we will analyze the acidic properties of these oxides based on the electronegativity of their central atoms and their positions in the periodic table.

### Step-by-Step Solution:

1. **Identify the Oxides**: The oxides given are:
- Al₂O₃ (Aluminum oxide)
- MgO (Magnesium oxide)
- Na₂O (Sodium oxide)
- CO (Carbon monoxide)

2. **Determine the Period and Group**:
- Al₂O₃ contains Aluminum (Al), which is in Group 13 of the periodic table.
- MgO contains Magnesium (Mg), which is in Group 2.
- Na₂O contains Sodium (Na), which is in Group 1.
- CO contains Carbon (C), which is in Group 14.

3. **Analyze Electronegativity**:
- Electronegativity increases from left to right across a period and decreases from top to bottom within a group.
- In the third period:
- Sodium (Na) has the lowest electronegativity.
- Magnesium (Mg) has a higher electronegativity than Sodium.
- Aluminum (Al) has a higher electronegativity than both Sodium and Magnesium.
- Carbon (C) has a higher electronegativity than Aluminum, Magnesium, and Sodium.

4. **Compare Acidic Strength**:
- The acidic strength of oxides is directly proportional to the electronegativity of the central atom.
- Therefore, the order of acidic strength based on electronegativity is:
- CO (C has the highest electronegativity)
- Al₂O₃ (Al has a higher electronegativity than Mg and Na)
- MgO (Mg has a lower electronegativity than Al)
- Na₂O (Na has the lowest electronegativity)

5. **Conclusion**:
- Among the given options, CO is the strongest acidic oxide due to the high electronegativity of Carbon.

### Final Answer:
The strongest acidic oxide among the options is **CO**.