The catalyst used in the dehydration of ethylalcohol to ethene is 

Options

A. `Al_(2)O_(3)`
B. `Sb_(2)O_(3)`
C. `As_(2)O_(3)`
D. `Cu`

Answer

To solve the question regarding the catalyst used in the dehydration of ethyl alcohol (ethanol) to ethene, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction**: The dehydration of ethyl alcohol (ethanol) involves the removal of a water molecule (H₂O) from the ethanol molecule (C₂H₅OH) to form ethene (C₂H₄).

2. **Write the Chemical Equation**: The chemical equation for the dehydration of ethanol can be represented as:
\[ \text{C}_2\text{H}_5\text{OH} \rightarrow \text{C}_2\text{H}_4 + \text{H}_2\text{O} \]

3. **Determine the Catalyst**: A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. In this case, we need to identify which of the given options acts as a catalyst for this reaction.

4. **Analyze the Options**:
- **Option 1: Al₂O₃ (Aluminum Oxide)**: This is commonly used as a catalyst in dehydration reactions.
- **Option 2: Sb₂O₃ (Antimony Trioxide)**: Not typically used for this reaction.
- **Option 3: As₂O₃ (Arsenic Trioxide)**: Also not commonly used for this reaction.
- **Option 4: Copper**: While copper can act as a catalyst in some reactions, it is not the primary catalyst for the dehydration of ethanol.

5. **Conclusion**: Based on the analysis, aluminum oxide (Al₂O₃) is the catalyst used for the dehydration of ethyl alcohol to ethene. Therefore, the correct answer is:
\[ \text{Answer: Al}_2\text{O}_3 \]