In the molecule $C_2{H}_2$ (ethyne), how many carbon atoms are $\mathrm{sp}$ hybridized?

• A. $1$
• B. $4$
• C. $0$
• D. $2$

Answer: (D)

Verified step by step guidance

1. Identify the molecular formula and structure of ethyne (C\_2H\_2). Ethyne is a linear molecule with a triple bond between the two carbon atoms.
2. Recall that the hybridization of a carbon atom depends on the number and types of bonds it forms. For a carbon atom with a triple bond, the hybridization is typically sp.
3. Analyze the bonding in ethyne: each carbon atom forms one sigma bond with the other carbon and one sigma bond with a hydrogen atom, plus two pi bonds between the carbons, making a triple bond overall.
4. Since each carbon in ethyne forms two sigma bonds and has two pi bonds, the hybridization of each carbon is sp, which involves mixing one s orbital and one p orbital to form two sp hybrid orbitals.
5. Conclude that both carbon atoms in ethyne are sp hybridized, so the number of sp hybridized carbon atoms is 2.