In context with the industrial preparation of hydrogen from water gas `(CO+H_(2))` , which of the following is the correct statement ?

Options

A. `CO` is removed by absorption in aqueous `Cu_(2)Cl_(2)` Solution.
B. `H_(2)` is removed through occlusiion with `Pd`.
C. `CO` is oxidized to `CO_(2)` with steam in the presence of a catalyst, followed by absorption of `CO_(2)` in alkali.
D. `CO` and `H_(2)` are fractionally separated using differences in their densities.

Explanation

To solve the question regarding the industrial preparation of hydrogen from water gas (CO + H₂), we will analyze the process and determine which statement is correct based on the information provided.

### Step-by-Step Solution:

1. **Understanding Water Gas**: Water gas is a mixture of carbon monoxide (CO) and hydrogen (H₂). It is produced by passing steam over hot carbon (usually in the form of coke).

2. **Conversion of CO to CO₂**: In the industrial preparation of hydrogen, carbon monoxide (CO) is converted to carbon dioxide (CO₂) by reacting it with steam (H₂O) in the presence of a catalyst. The reaction can be represented as:
\[ CO + H₂O \xrightarrow{\text{Catalyst}} CO₂ + H₂ \]
This step is crucial as it highlights the transformation of CO into CO₂ while generating additional hydrogen gas.

3. **Catalysts Used**: The catalysts mentioned in the process are iron (III) oxide (Fe₂O₃) and chromium (III) oxide (Cr₂O₃). These catalysts facilitate the reaction between carbon monoxide and steam.

4. **Separation of Gases**: After the reaction, the resulting mixture contains hydrogen gas (H₂) and carbon dioxide (CO₂). The carbon dioxide can be absorbed by alkaline solutions, while hydrogen remains unabsorbed. This separation can be achieved because CO₂ is soluble in water and reacts with alkalis to form carbonates.

5. **Evaluating the Statements**: Now, we need to evaluate the statements provided in the question:
- **Statement 1**: CO is removed by absorption. (Incorrect, as CO is not absorbed; it is converted to CO₂.)
- **Statement 2**: H₂ is removed by this method. (Incorrect, as H₂ is not removed through absorption.)
- **Statement 3**: CO is oxidized to CO₂ with steam in the presence of a catalyst. (Correct, as this is the main reaction occurring in the process.)
- **Statement 4**: Cu and H₂ are fractionally separated using differences in their densities. (Incorrect, as this method is not used for separating CO and H₂.)

6. **Conclusion**: The correct statement regarding the industrial preparation of hydrogen from water gas is that carbon monoxide is oxidized to carbon dioxide with steam in the presence of a catalyst.

### Final Answer:
The correct statement is: **CO is oxidized to CO₂ with steam in the presence of a catalyst.**

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