Question

4. Which of the following could be antiaromatic (assuming sp' hybridization)? A. IV B. I C. III D. II E. None I III IV A. IV B. I c. II D. III E. None 6. Which is the correct bond order for the C-C bonds in benzene? A. III B. C. V D. II E. None 2
please help!

Answer 1

4) The non aromatic compound is: Option B) 1

As compound 1 has 8 pi electrons (4n) ( 2 from each double bonds and two each from one lone pair of both s and O) and it is cyclic planner and its all atoms are sp2 hybridized. Compound 2 is not planner as the hydroxyl group containing carbon is sp3 hybridized so it is non aromatic and both compound 3 and 4 are cyclic planner systems with sp2 hybridised atoms with 6 pi and 2 pi electrons ( 4n+2) respectively so both are aromatic compounds.

5) A) Compound 4 is non aromatic as the eight membered ring will not be a planner system so it will be a non aromatic compound. While Compound 1 and 2 both are cyclic planner systems with sp2 hybridised atoms and both has 6 pi electrons (4n+2) so they both will be aromatics and compound 3 will be anti aromatic as it is a cyclic planner systems with sp2 hybridised atoms having 8 pi electrons (4n six from three double bonds and two from O lone pair).

6)The bond order of benzene is Option A) 3.

As the benzene ring has two canonical structures with the bond order between any two adjacent carbons be 2 and 1 in two canonical forms so overall bond order becomes an average of those two that is 1.5 for all bonds.