Question

Which of the following Lewis structures is correct for C₂H₂?

(a) H-C=C-H
(b) H-C≡C-H
(c) H-C-C-H
(d) H-C≡C≡H

Answer 1

The correct Lewis structure for C₂H₂ is option (b) H-C≡C-H. The carbon atoms are sp hybridized, creating a linear geometry with a 180° bond angle around each carbon atom in the molecule.

Step-by-step explanation:

The correct Lewis structure for C₂H₂ is option (b) H-C≡C-H. This structure indicates that there are a triple bond and two single bonds in the molecule. The triple bond between the two carbon atoms consists of one sigma (σ) bond and two pi (π) bonds. Each carbon atom also forms a single bond with a hydrogen atom (C-H), completing the structural formula for acetylene.

The geometry around each carbon atom in acetylene is linear because of the sp hybridization that occurs due to the triple bond. The hydrogen atoms are bonded to the carbon atoms in a way that creates a straight molecule with an angle of 180° between the bonded atoms.

The hybridization of each carbon atom in acetylene is sp; each carbon atom uses one s orbital and one p orbital for the sigma bonds in the triple bond and the single bonds to hydrogen, leaving two p orbitals to form the two pi bonds.