Which of the following is most acidic

Options

A. `Na_(2)O`
B. MgO
C. `Al_(2)O_(3)`
D. CaO

Explanation

To determine which of the given oxides is the most acidic, we can follow these steps:

### Step 1: Identify the Oxides
List the oxides provided in the question. For this example, let's assume we have the following oxides: Na2O, MgO, Al2O3, and SiO2.

### Step 2: Classify the Oxides
Classify each oxide as either acidic, basic, or amphoteric:
- **Basic Oxides**: Na2O (sodium oxide), MgO (magnesium oxide)
- **Amphoteric Oxide**: Al2O3 (aluminium oxide)
- **Acidic Oxide**: SiO2 (silicon dioxide)

### Step 3: Understand the Acid-Base Nature
Recall that:
- Metals generally form basic oxides.
- Non-metals generally form acidic oxides.
- Amphoteric oxides can act as either acids or bases depending on the conditions.

### Step 4: Compare the Oxides
From the classification:
- Na2O and MgO are basic.
- Al2O3 is amphoteric, meaning it can exhibit both acidic and basic properties.
- SiO2 is acidic.

### Step 5: Determine the Most Acidic Oxide
Among the oxides listed:
- SiO2 is the most acidic oxide as it is a non-metal oxide.
- Al2O3, being amphoteric, is less acidic than SiO2.

### Conclusion
Therefore, the most acidic oxide among the given options is **SiO2**.

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