When ethene is heated at `400^@` C Under high pressure, the product is are

Options

A. Carbon and `H_2`
B. Polyethylene
C. Acetylene and `H_2`
D. None of these

Explanation

To solve the question regarding the products formed when ethene is heated at 400°C under high pressure, we can follow these steps:

### Step 1: Understand the Structure of Ethene
Ethene (C₂H₄) is an alkene with a double bond between the two carbon atoms. Its structure can be represented as:
\[ \text{H}_2C=CH_2 \]

### Step 2: Identify the Conditions
The question specifies that ethene is heated at a temperature of 400°C under high pressure. These conditions are conducive to a chemical process known as polymerization.

### Step 3: Describe the Polymerization Process
Under high temperature and pressure, the double bond in ethene can break, allowing the individual ethene molecules to link together. This process is called polymerization, where small monomer units (in this case, ethene) combine to form a larger polymer.

### Step 4: Write the Reaction
The polymerization of ethene can be represented as:
\[ n \, \text{C}_2\text{H}_4 \rightarrow \text{(C}_2\text{H}_4\text{)}_n \]
This indicates that 'n' molecules of ethene combine to form a polymer.

### Step 5: Identify the Product
The product of this polymerization reaction is polyethylene, a common plastic used in various applications. The structure of polyethylene consists of long chains of repeating ethylene units.

### Conclusion
Thus, when ethene is heated at 400°C under high pressure, the product formed is polyethylene.

### Final Answer
The product is polyethylene (option number 2).

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