Potassium nitrate is called

Options

A. Mohr's salt
B. Gypsum
C. Indian salt petre
D. Chile salt petre

Answer

To answer the question "Potassium nitrate is called," we need to identify the common name or term associated with potassium nitrate.

### Step-by-Step Solution:

1. **Identify the Chemical Formula**:
- Potassium nitrate is a chemical compound with the formula KNO₃.

2. **Common Names**:
- Potassium nitrate is commonly known as "saltpeter" or "niter."

3. **Contextual Understanding**:
- It is important to note that potassium nitrate has historical significance and has been used in fertilizers, food preservation, and in the manufacture of explosives.

4. **Conclusion**:
- Therefore, the answer to the question is that potassium nitrate is commonly referred to as "saltpeter."

### Final Answer:
Potassium nitrate is called **saltpeter**.

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