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- Solutions 16

In each of the following pairs, determine whether the two represent resonance contributors of a single species or depict different substances. If two structures are not resonance contributors, explain why.

So, let's go ahead and pay attention to these two molecules up here, this pair and figure out if they're resonance structures of if they're entirely different molecules. Remember, for resonance structures a couple of rules that we need to follow, right? one we can't have our atoms moving around right, only electrons move, the next rule is that we have the same number of electrons and as a consequence to that our net charge on the molecule will stay the same, right? No matter what arrangement it's in, you can have two negatives and a positive but you have a negative one charge net, right? You should expect the negative one charge to remain throughout all your other resonance structures for example, right? It could be any charge, so now let's go ahead and take a look and figure out our formal charges, so this one has three lone pairs and one bond, right? We know the nitrogen likes to have three bonds and one lone pair, so this has a two negative charge, right? this guy over here, we can also do our sticks plus dots, right? So, our group number is five minus 1 stick and 6 dots, right? So that's five minus seven, that's going to give us negative two, this next one over here, nitrogen likes to have three bonds and one lone pair but it's got four bonds here, so it's got a positive charge, right? And then this next one has a 1, 2, 3, right? 3 bonds and a lone pair, which is exactly what it wants so it's got a net zero charge, okay? So this whole thing, this whole molecule has a net charge of negative one. Alright, so now this next one here, this has two bonds and two lone pairs, so it's got a negative charge, this one has a positive charge, so it's also got four bonds just like this one, right? And then this one over here has a negative charge, so the net of this molecule is a negative charge, so what does that tell me? that tells me guys that these are resonance structures, okay? So if you have any questions please feel free to let me know, if not, let's move on to the next problem.