Which statement about the length of carbon–carbon single, double, and triple bonds is true?

Study for the Medical Chemistry Test. Explore multiple choice questions with hints and explanations. Get exam-ready with engaging quizzes and comprehensive study materials.

Bond length tracks how strongly atoms share electrons—the higher the bond order, the shorter the bond. A carbon–carbon triple bond has three shared pairs of electrons, compared with one for a single bond and two for a double bond. The sigma component in a C≡C bond comes from sp-hybridized orbitals, which have more s-character and pull the nuclei closer together, while the two pi bonds lock the atoms in tighter. This combination yields the shortest distance between the carbon nuclei. In practice, C–C single bonds are about 1.54 Å, C=C double bonds around 1.34 Å, and C≡C triple bonds near 1.20 Å, so the triple bond is shorter than both the single and the double.