Question

which bond would you expect to have the highest bond energy?
○ the c≡c in c₂h₂
○ the c-c bond in c₂h₆
○ all of the bonds should have the same energy, because they are all bonds between carbon atoms.
○ the c=c bond in c₂h₄

Explanation:

Bond energy is related to the bond order (number of shared electron pairs). A triple bond (C≡C) has a higher bond order than a double (C=C) or single (C - C) bond. Higher bond order means more energy is required to break the bond, so triple bonds have the highest bond energy. In \( \ce{C2H2} \), the carbon - carbon bond is a triple bond (\( \ce{C≡C} \)), in \( \ce{C2H6} \) it is a single bond (\( \ce{C - C} \)), and in \( \ce{C2H4} \) it is a double bond (\( \ce{C=C} \)). The option claiming all carbon - carbon bonds have the same energy is incorrect because bond order (and thus energy) varies with the type of bond (single, double, triple).

Answer:

The \( \ce{C≡C} \) in \( \ce{C2H2} \)