The product formed when acetylene is passed through red hot tube is

Options

A. benzene
B. cyclohexane
C. neoprene
D. ethane

Explanation

To determine the product formed when acetylene is passed through a red-hot iron tube, we can follow these steps:

### Step 1: Understand the Reactants
Acetylene, also known as ethyne (C₂H₂), is a simple alkyne with a triple bond between two carbon atoms.

**Hint:** Acetylene is a hydrocarbon that can undergo various reactions under different conditions.

### Step 2: Identify the Reaction Conditions
The reaction occurs in a red-hot iron tube, which indicates that high temperatures (around 873 K) are involved. The presence of iron suggests that it may act as a catalyst.

**Hint:** High temperatures can lead to different types of reactions, including polymerization.

### Step 3: Consider the Type of Reaction
Under these conditions, acetylene can undergo cyclic polymerization. This means that multiple acetylene molecules can react together to form larger cyclic structures.

**Hint:** Look for reactions that involve the combination of multiple small molecules to form larger ones.

### Step 4: Determine the Product
When three molecules of acetylene undergo cyclic polymerization, they can form benzene (C₆H₆). This is a well-known reaction where acetylene is converted into aromatic compounds.

**Hint:** Aromatic compounds like benzene are often formed from the polymerization of smaller hydrocarbons.

### Step 5: Conclusion
The product formed when acetylene is passed through a red-hot iron tube is benzene.

**Final Answer:** Benzene