Red hot coke+Steam`overset(1000^(@)C)tounderset("Steam")underset(uarr)(X)overset(500^(@)C)underset("Catalyst(Y))to(Z)+H_(2)`
`'Z'` is

Options

A. `CO`
B. `CO_(2)`
C. `O_(2)`
D. `H_(2)O`

Explanation

To solve the question, we need to analyze the given reaction step by step.

### Step 1: Identify the Reactants
The reaction begins with red hot coke and steam.
- Red hot coke is essentially carbon (C) in solid form.
- Steam is water (H2O) in gaseous form.

### Step 2: Write the First Reaction
The first reaction occurs at a temperature of 1000°C (or 1273 K). The reaction can be written as:
\[ C (s) + H_2O (g) \rightarrow CO (g) + H_2 (g) \]
This reaction produces carbon monoxide (CO) and hydrogen gas (H2). The mixture of CO and H2 is known as water gas.

### Step 3: Identify the Second Reaction
The water gas produced (CO + H2) undergoes further reaction at a lower temperature of 500°C (or 773 K) in the presence of a catalyst (Y). The catalyst can be iron chromite (FeCrO4) or other similar compounds.

### Step 4: Write the Second Reaction
In this step, the water gas reacts with steam again:
\[ CO (g) + H_2O (g) \overset{Y}{\rightarrow} CO_2 (g) + H_2 (g) \]
This reaction produces carbon dioxide (CO2) and additional hydrogen gas (H2).

### Step 5: Identify the Product Z
From the second reaction, we can see that the product Z is carbon dioxide (CO2).

### Final Answer
Thus, the answer to the question is:
\[ Z = CO_2 \]

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