Which of the following is a synthesis gas?

Options

A. `CO+N_(2)`
B. `CO+H_(2)`
C. `CO+O_(2)`
D. `CO+Cl_(2)`

Explanation

To determine which of the given options is a synthesis gas, we need to understand the definition and composition of synthesis gas.

### Step-by-Step Solution:

1. **Definition of Synthesis Gas**: Synthesis gas, commonly referred to as syngas, is a mixture of carbon monoxide (CO) and hydrogen (H2). It may also contain small amounts of carbon dioxide (CO2).

2. **Composition of Synthesis Gas**: The primary components of synthesis gas are:
- Carbon monoxide (CO)
- Hydrogen (H2)
- Traces of carbon dioxide (CO2)

3. **Uses of Synthesis Gas**:
- It is used as a fuel.
- It serves as a feedstock for chemical synthesis, which means it is used as a raw material in the production of various chemicals.

4. **Analyzing Options**:
- We need to look at the options provided and identify which one contains the components of synthesis gas (CO and H2).
- If an option lists CO and H2 together, that option represents synthesis gas.

5. **Identifying Other Gases**:
- **Producer Gas**: This is a mixture of carbon monoxide and nitrogen (CO + N2). It is not synthesis gas.
- **Phosgene Gas**: This is produced from the reaction of carbonyl chloride (COCl2) and is toxic. It is not synthesis gas.
- **Carbon Dioxide**: This is produced when carbon monoxide reacts with oxygen (O2) and is not synthesis gas.

6. **Conclusion**: Based on the analysis, the option that contains carbon monoxide and hydrogen together is the synthesis gas.

### Final Answer:
The correct option that represents synthesis gas is the one that contains carbon monoxide (CO) and hydrogen (H2).

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