Which of the following is used as a white pigment?

Options

A. `ZnO`
B. `Na_2ZnO_2`
C. `ZnS`
D. `ZnCO_3`

Answer

To determine which of the following is used as a white pigment, we can analyze the options provided, focusing on the compounds associated with zinc.

### Step-by-Step Solution:

1. **Identify the Options**:
- We need to identify the compounds that are typically used as white pigments. The common options include zinc oxide, zinc sulfide, and zinc carbonate.

2. **Understand White Pigments**:
- White pigments are substances that provide a white color and opacity to materials. They are commonly used in paints, coatings, and other applications.

3. **Evaluate Each Compound**:
- **Zinc Oxide (ZnO)**: This compound is widely used as a white pigment. It is known for its excellent opacity and is commonly found in paints and adhesives.
- **Zinc Sulfide (ZnS)**: While this compound can be used in some applications, it is not as commonly used as a white pigment compared to zinc oxide.
- **Zinc Carbonate (ZnCO3)**: This compound is not typically used as a white pigment in the same way that zinc oxide is.

4. **Conclusion**:
- Among the options provided, **Zinc Oxide (ZnO)** is the most commonly used white pigment. It is favored for its properties in paints and adhesives.

### Final Answer:
**Zinc Oxide (ZnO)** is used as a white pigment.

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