Question

Which of the following statements is incorrect for $\sigma$ and $\pi$-bonds formed between two carbon atoms?

• A. $\sigma$-bond is stronger than a $\pi$-bond
• B. Bond energies of $\sigma$ and $\pi$-bonds are of the order of $264kJ/mol$ and $347kJ/mol$
• C. Free rotation of surrounding atoms about a $\sigma$-bond is allowed but not in case of a $\pi$-bond
• D. $\sigma$-bond determines the direction between carbon atoms but a $\pi$-bond has no primary effect in this regard

Answer 1

The correct option is B Bond energies of $\sigma$ and $\pi$-bonds are of the order of $264kJ/mol$ and $347kJ/mol$

As $\sigma$-bond is stronger than a $\pi$-bond so it has higher energy than $\pi$-bond.
Free rotation of surrounding atoms about a $\sigma$-bond is allowed but not in case of a $\pi$-bond due to constrained motion.