[eglaud]

Attached is a review sheet for an upcoming exam, and I've run into a few problems with it. The biggest confusion stems from ranking the three bonds in terms of strength. If you look at the attachment, the answer in 2e talks about resonance structures by bond #2, but I don't see it? Also how would one determine an accurate bond order from the picture alone? Locally bond 2 and 3 look identical, so I'm having troubles differentiating them. Any help is welcome, thanks.

[tumblewush]

Looking at the problem, bond number 2 is part of a resonance because it's part of a benzene ring (which has no true representation when you think about it since the double bonds are continuously resonating). Didn't really use bond orders to do the ranking for this one, here's my thought process:

• Bond number 1 is a double bond that isn't involved in resonance. So it's got a shorter bond length among the three. Shorter bond length means the bond is stronger, that's why it's the strongest.
• Bond number 2 is part of a benzene ring and the double bond is involved in resonance. So it exists somewhere between having a single and a double bond. This makes it less stronger than the first one
• Bond number 3 is a single bond. Being a single bond, in comparison to the others it has a longer bond length and so is the weakest among the three.

[eglaud]

Looking at the problem, bond number 2 is part of a resonance because it's part of a benzene ring (which has no true representation when you think about it since the double bonds are continuously resonating). Didn't really use bond orders to do the ranking for this one, here's my thought process:

• Bond number 1 is a double bond that isn't involved in resonance. So it's got a shorter bond length among the three. Shorter bond length means the bond is stronger, that's why it's the strongest.
• Bond number 2 is part of a benzene ring and the double bond is involved in resonance. So it exists somewhere between having a single and a double bond. This makes it less stronger than the first one
• Bond number 3 is a single bond. Being a single bond, in comparison to the others it has a longer bond length and so is the weakest among the three.

Okay I did not know the benzene ring constantly resonates! Thank you