The gas which is present both in producer gas and in water gas is …………….

Explanation

To solve the question regarding the gas that is present in both producer gas and water gas, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Producer Gas**:
- Producer gas is a mixture of gases that is primarily produced from the gasification of carbonaceous materials. The main components of producer gas include:
- Carbon monoxide (CO)
- Hydrogen (H₂)
- Carbon dioxide (CO₂)
- Nitrogen (N₂)

2. **Understanding Water Gas**:
- Water gas is produced by passing steam over hot carbon (usually coke). The main components of water gas are:
- Carbon monoxide (CO)
- Hydrogen (H₂)

3. **Identifying Common Gases**:
- Now, we need to identify the gases that are common to both producer gas and water gas.
- From the components listed:
- Producer gas: CO, H₂, CO₂, N₂
- Water gas: CO, H₂

4. **Finding the Common Gas**:
- The gases that appear in both lists are:
- Carbon monoxide (CO)
- Hydrogen (H₂)
- However, the question specifically asks for the gas that is present in both, and since carbon monoxide is a significant component in both mixtures, it is the most relevant answer.

5. **Conclusion**:
- Therefore, the gas which is present in both producer gas and water gas is **carbon monoxide (CO)**.

### Final Answer:
The gas which is present both in producer gas and in water gas is **carbon monoxide (CO)**.

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