The preparation of benzene from acetylene (C₂H₂) can also be described as ?

The preparation of benzene from acetylene (C₂H₂) is an important reaction in organic chemistry. This process is known as polymerization, where three molecules of acetylene combine under specific conditions to form benzene (C₆H₆). The reaction occurs when acetylene is passed through a red-hot iron tube or heated over a catalyst such as ferric or nickel oxide at high temperatures (around 600°C).

The chemical equation for this transformation is:

3C2H2→heatC6H63C_2H_2 \xrightarrow{heat} C_6H_63C2H2heatC6H6

This reaction involves the trimerization of acetylene — a specific type of polymerization in which three molecules join to form a single cyclic compound. The process converts simple unsaturated hydrocarbon molecules (alkynes) into an aromatic compound, benzene, which has a stable ring structure due to delocalized π-electrons.

In this reaction, no oxidation, reduction, or dehydration occurs; instead, multiple acetylene molecules link through carbon–carbon bond formation. The reaction showcases how multiple unsaturated units can combine to create an aromatic ring — a fundamental concept in the chemistry of hydrocarbons.

The polymerization of acetylene to benzene is also an example of how unsaturated compounds can undergo ring formation through heat or catalysts. Industrially, this reaction illustrates how simpler hydrocarbons can serve as starting materials for the production of aromatic compounds, which are essential in the manufacture of dyes, plastics, solvents, and drugs.

Thus, the preparation of benzene from acetylene represents a classic polymerization reaction — a process that transforms linear unsaturated molecules into a stable aromatic system with high resonance energy