Water gas is produced by

Options

A. passing steam through a red hot coke bed
B. saturing hydrogen with moisture
C. mixing oxygen and hydrogen in the ratio of `1 : 2`
D. heating a mixture of `CO_(2)` and `CH_(4)` in petroleum refineries

Explanation

To determine how water gas is produced, let's analyze the options provided in the question step by step.

### Step 1: Understand what water gas is
Water gas is a mixture of two gases: carbon monoxide (CO) and hydrogen (H2). It is produced through specific chemical reactions involving carbon and water.

### Step 2: Analyze the options
1. **Passing steam through a red hot coke bed**: This involves introducing steam (water vapor) to a bed of red hot coke (carbon). The reaction occurs as follows:
\[ \text{C (s)} + \text{H}_2\text{O (g)} \rightarrow \text{CO (g)} + \text{H}_2\text{(g)} \]
This reaction produces carbon monoxide and hydrogen, which together form water gas.

2. **Saturating hydrogen with moisture**: This option does not produce water gas. Saturating hydrogen with moisture would not lead to the formation of CO and H2.

3. **Mixing oxygen and nitrogen in the ratio of 1:2**: This option does not relate to the production of water gas. Oxygen and nitrogen do not react to produce carbon monoxide or hydrogen.

4. **Heating a mixture of CO2 and CH4 in petroleum refineries**: This process is known as reforming, which can produce hydrogen but does not directly produce water gas as defined (CO and H2).

### Step 3: Conclusion
The only option that correctly describes the production of water gas is:
- **Option A: Passing steam through a red hot coke bed**.

### Final Answer
Water gas is produced by **passing steam through a red hot coke bed**.

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