Azo dyes are organic dyes that are used for many applications, such as the coloring of fabrics. Many azo dyes are derivatives of the organic substance azobenzene, C12H10N2. A closely related substance is hydrazobenzene, C12H12N2. The Lewis structures of these two substances are

(Recall the shorthand notation used for benzene.) (b) How many unhybridized atomic orbitals are there on the N and the C atoms in each of the substances? How many unhybridized atomic orbitals are there on the N and the C atoms in hydrazobenzene?

Video transcript

Hello everyone. So in this video we're given this structure of indigo. I was trying to see how many and hybridized orbital's are in our nitrogen and carbon atoms. So we're given a hint that due to resonance stabilization and authenticity, nitrogen will be sp two hybridized. So these two nitrogen atoms are exactly the same and they're both sp two hybridized and because of that then we know that nitrogen atoms here are two on hybridized orbital's for those items. So right off the bat Because of the hint, we can go ahead and just say that nitrogen has to hybridized orbital's. Alright, so now we're looking for other sp two hybridized carbon atoms now instead of the nitrogen. And this just means that the carbon will have to have three groups attached to it. So let's start on the far left, right over here. So when I say three groups, it just needs to mean three other atoms. So we have starting off with this one, then it's attached to one hydrogen and two carbons. So that's three groups as sp two hybridized. If you took a look at this entire ring actually, they're all sp two hybridized carbon atoms. So let's start to count. We have one, two, three, 4, 5 and six, nitrogen does not count because we already did those. So we have one carbon here and one carbon here. So for this carbon is connected to two other carbons and one oxygen. So that's three groups total. This carbon here is connected to another carbon, nitrogen and another carbon. So two carbons and one nitrogen again is three groups. So again, we have our sp two hybridized carbons, so continue to count at seven and eight. Moving on to this ring here again. This is an sp two hybridized same here. Same here and same here. So continue our count. We have then 9, 10, 11 and 12. The four right ring is basically the same as this. And again, we have all sp two hybridized carbons. So continuing the count, we stopped at 12. So I have 13, 14, 15 and 16. So we have 16 sp two hybridized carbon atoms. So there's gonna be 16 in hybridized atomic orbital's for our carbon atoms. So a total then for this entire structure will have 18 and hybridized orbital's. But nitrogen will have two carbon will have 16. So that's going to be my final answer for this question. Thank you all so much for watching.