Catalyst used in polymerization of ethen is:

Options

A. `TiCl_(4)` and `AIR_(3)`
B. `Fe,Co`
C. `H_(3)PO_(4)`
D. `Zeolites

Explanation

To determine the catalyst used in the polymerization of ethene, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Polymerization**: Polymerization is a chemical process where small molecules called monomers combine to form a larger molecule known as a polymer. In this case, the monomer is ethene (C2H4).

2. **Identify the Type of Polymerization**: The polymerization of ethene occurs through a process called addition polymerization. This involves the addition of monomer units without the loss of any small molecules.

3. **Recognize the Monomer**: The monomer for the polymerization in question is ethene (C2H4). When many ethene molecules combine, they form polyethylene, which is a common plastic.

4. **Identify the Catalyst**: The polymerization of ethene is catalyzed by a specific type of catalyst known as Ziegler-Natta catalyst. This catalyst is crucial for the process as it allows the polymerization to occur under milder conditions and with better control over the polymer structure.

5. **Components of Ziegler-Natta Catalyst**: The Ziegler-Natta catalyst is typically a combination of titanium compounds (such as titanium tetrachloride, TiCl4) and aluminum alkyls (such as aluminum triethyl, Al(C2H5)3). These components work together to facilitate the polymerization reaction.

6. **Select the Correct Option**: Based on the information above, the correct answer to the question is option A, which refers to titanium chloride (TiCl4) and aluminum alkyl (AlR3).

### Final Answer:
The catalyst used in the polymerization of ethene is **Ziegler-Natta catalyst**, specifically a mixture of **titanium chloride (TiCl4)** and **aluminum alkyl (AlR3)**.

---