What is the chemical formula of acetylene?

The correct answer is C2H2, which is the chemical formula for acetylene. Acetylene is a colorless gas that is known for its use in welding and as a building block for various chemical syntheses.

To understand why C2H2 is correct, it's important to break down its molecular structure. In acetylene, there are two carbon atoms and two hydrogen atoms. The two carbon atoms are connected by a triple bond, which makes acetylene a member of the alkyne family of hydrocarbons. This triple bond is significant because it greatly affects the properties of the compound, particularly its reactivity and energy content, making acetylene a highly efficient fuel.

In contrast, the other formulas provided correspond to different hydrocarbons. C2H6 is ethane, a saturated hydrocarbon with single bonds. C3H8 is propane, another saturated hydrocarbon, and also has single bonds. C4H10 refers to butane, which is again a saturated hydrocarbon. None of these compounds feature the triple bond characteristic of acetylene, which is essential to its identity. Therefore, the molecular formula for acetylene being C2H2 uniquely identifies it among the options given.