Which of the following is not amphoteric oxide ?

Options

A. `ZnO`
B. `BeO`
C. `Al_(2)O_(3)`
D. `CrO_(3)`

Explanation

To determine which of the following oxides is not an amphoteric oxide, we need to understand what amphoteric oxides are and analyze the given options.

### Step 1: Define Amphoteric Oxides
Amphoteric oxides are oxides that can react with both acids and bases. This means they can act as either an acid or a base depending on the reaction conditions.

### Step 2: Analyze Each Option
1. **Zinc Oxide (ZnO)**:
- ZnO reacts with acids to form zinc salts and with bases to form zincates. Therefore, ZnO is an amphoteric oxide.

2. **Beryllium Oxide (BeO)**:
- BeO reacts with acids (like sulfuric acid) to form beryllium sulfate and with bases (like NaOH) to form beryllium hydroxide. Thus, BeO is also an amphoteric oxide.

3. **Aluminum Oxide (Al2O3)**:
- Al2O3 reacts with acids to form aluminum salts and with bases to form aluminate ions. Hence, Al2O3 is an amphoteric oxide.

4. **Chromium Trioxide (CrO3)**:
- CrO3 reacts only with acids and does not react with bases. Therefore, CrO3 is not an amphoteric oxide.

### Step 3: Conclusion
Based on the analysis, the oxide that is not amphoteric is **Chromium Trioxide (CrO3)**.

### Final Answer
**CrO3 is not an amphoteric oxide.**

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