(See attached file for full problem description)
a. The structure of 1,3-butadiene is usually written as H2C==CH--CH==CH2. The average bond lengths given are: C--C of 154pm and C==C of 133pm. Explain the fact that the observed value of the distance between the two central carbon atoms in 1,3-butadiene is 146pm.
b. Which of the attached three possible resonance structures would make the greatest contribution to the resonance hybrid? Explain your answer.
c. Cinnamaldehyde (structure attached) gives the spice cinnamon its characteristic odor. How many signma bonds and how many pi bonds are in this molecule?
Three questions on bond structures, resonance structures, and the types of bonds within the given molecule structures.