Which of the following substance can be used for drying neutral or basic gases?

Options

A. Calcium carbonate
B. Sodium carbonate
C. Sodium bicarbonate
D. Calcium oxide

Answer

To determine which substance can be used for drying neutral or basic gases, we need to analyze the properties of the given substances: calcium carbonate (CaCO3), sodium carbonate (Na2CO3), sodium bicarbonate (NaHCO3), and calcium oxide (CaO).

### Step-by-Step Solution:

1. **Understanding Drying Agents**:
- A drying agent is a substance that removes moisture from gases. It is essential for drying neutral or basic gases without reacting with them.

2. **Identifying the Substances**:
- The substances provided are:
- Calcium Carbonate (CaCO3)
- Sodium Carbonate (Na2CO3)
- Sodium Bicarbonate (NaHCO3)
- Calcium Oxide (CaO)

3. **Analyzing Each Substance**:
- **Calcium Carbonate (CaCO3)**: This is a salt and is not typically used as a dehydrating agent because it can react with acidic gases.
- **Sodium Carbonate (Na2CO3)**: This is also a salt and may react with acidic gases, making it unsuitable for drying neutral or basic gases.
- **Sodium Bicarbonate (NaHCO3)**: This is a weak acid salt and can react with basic gases, so it is not a good choice for drying.
- **Calcium Oxide (CaO)**: This is a basic oxide and is known for its dehydrating properties. It can absorb moisture without reacting with neutral or basic gases, making it an effective drying agent.

4. **Conclusion**:
- Among the given substances, **Calcium Oxide (CaO)** is the most suitable for drying neutral or basic gases.

### Final Answer:
**Calcium Oxide (CaO)** can be used for drying neutral or basic gases.

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