Which of the following metal oxide is white in colour but become yellow on heating

Options

A. `AgO`
B. `ZnO`
C. `Ag_(2)O`
D. `FeO`

Answer

To determine which metal oxide is white in color but becomes yellow on heating, we can analyze the properties of the given options step by step.

### Step-by-Step Solution:

1. **Identify the Metal Oxides:**
- We need to analyze the color properties of the following metal oxides:
- Silver Oxide (AgO)
- Zinc Oxide (ZnO)
- Silver Peroxide (Ag2O)
- Iron Oxide (FeO)

2. **Examine Each Metal Oxide:**
- **Silver Oxide (AgO):**
- Color: Black or brown.
- Conclusion: Does not meet the criteria.

- **Zinc Oxide (ZnO):**
- Color: White.
- Upon heating, it changes to yellow.
- Conclusion: Meets the criteria (white to yellow on heating).

- **Silver Peroxide (Ag2O):**
- Color: Black or brown.
- Conclusion: Does not meet the criteria.

- **Iron Oxide (FeO):**
- Color: Black.
- Conclusion: Does not meet the criteria.

3. **Final Conclusion:**
- Among the given metal oxides, the only oxide that is white in color and becomes yellow upon heating is **Zinc Oxide (ZnO)**.

4. **Answer:**
- The correct answer is **Zinc Oxide (ZnO)**.