Mothballs are composed of naphthalene, C₁₀H₈, a molecule that consists of two six-membered rings of carbon fused along an edge, as shown in this incomplete Lewis structure:

(c) Not all of the C—C bond lengths in naphthalene are equivalent. Based on your resonance structures, how many C—C bonds in the molecule do you expect to be shorter than the others?

Video transcript

Hello everyone today, we are being shown and proceed C 14 H 10 a tricyclic aromatic compound that consists of 36 members rings fused with each other along the edges. Lewis structure of anthropocene is shown below. Now it's expected that all of the bonds, despite the residents will not be equivalent in terms of their bond lengths, how many C. C bonds are expected to be greater in bond length than the other C. C bonds. So the first thing I wanna do is you want to note the different resonant structures for anthropocene? So we have the original here and we're just going to draw them out On the side one x 1. So we have our three carbon structure here. Now, I'm not gonna draw in the hydrogen as they are implicitly implied that they are there last but not least we have our final structure. And these are our resident structures now know that there are a total of eight bonds that show up more times as single bonds than double bonds in the resident structures above. And these bonds are going to be highlighted as such. So we're gonna draw our three ring structure here with the double bonds missing. I'm gonna highlight where these single bonds show up majority of the time. So these are the eight single bonds that show up a lot more times as single bonds than double bonds. As a general rule, the length of a bond between atoms decreases as the number of shared electrons electron pairs increases. Or in other words, a single bond is longer than a double bond. So a single bond is longer than a double bond, and so the highlighted eight bonds that I highlighted just now will be those bonds that will be longer than the double bonds. I hope this helped, and until next time.