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Solution: In each of the following pairs, determine whether the two re...

Question

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. 

Video Transcript

So that for this middle pair, let's go ahead and do the exact same thing as we do for the first pair. So, here we know that this is the exact same thing, right? so I'm just going to go ahead and write two negative, positive and actually neutral for this one, okay? So, our net charge on this molecule is negative, but now this next molecule. Guys, there's a little something different here, right? Let me go ahead and fill this in just our lobe. So, to make our lone pairs more clear, guys, what does this look like? this looks a lot like this one but it's missing that third lone pair, right? So what do you think it's formal charges? you think it's going to be negative? actually guys, if we go ahead and do our group number minus sticks plus dots we know that our group number for nitrogen is 5, right? So let's go ahead and write this down because this one's a little bit tricky, group number minus sticks plus dots, okay? So, here we have our group number for nitrogen, is 5 minus, how many sticks does it have? one, how many does it have? 4. So guys, this is actually a neutral conformation for this nitrogen with fewer lone pairs, so it's actually going to have a zero formal charge, this next one, guys, hmm it should have a lone pair but it doesn't, right? It doesn't have a lone pair, so you know what that means guys? so if we go ahead and work this out, it's got a plus 2 charge, right? So I'm going to go ahead and put this here, 2 plus and then over here we've got two bonds and two lone pairs. So, how, what is that 5 minus 6, right? So that's number 5 minus 2 sticks and 4 dots, so it's 5 minus 6, we're going to get a negative charge here, so remember how I said that we should have the same charge between, the same net charge between two resonance structures? Well guys, here we have a negative charge and here we have a net positive charge, so these are entirely different, right? this one has 16 valence electrons if you count, this one has 14, okay? So this does not work for us. Alright guys, let me know if not let's move on.