Which one of the following represents the lowest energy $\pi$-bonding molecular orbital of 1,3-butadiene?
A) I
B) II
C) III
D) IV

Question

Which one of the following represents the lowest energy $\pi$-bonding molecular orbital of 1,3-butadiene? 
A) I 
B) II 
C) III 
D) IV

Quizplus · Accepted Answer

The lowest energy F1F1F1S1F1F1F10-bonding molecular orbital of 1,3-butadiene is anti-bonding in nature, which means it has a nodal plane between C1 and C2 as well as between C3 and C4. Looking at the diagram, it is clear that the MO labeled III has these nodal planes and thus represents the lowest energy F1F1F1S1F1F1F10-bonding molecular orbital of 1,3-butadiene.

Which One of the Following Represents the Lowest Energy π\piπ -Bonding Molecular Orbital of 1,3-Butadiene? A) I B) II

Which One of the Following Represents the Lowest Energy $\pi$ -Bonding Molecular Orbital of 1,3-Butadiene?
A) I
B) II