Write the Lewis structure for each molecule (octet rule not followed). a. BBr3 b. NO c. ClO2

Video transcript

Hey everyone, we're told that the following molecules are exceptions to the octet rule. Let's go ahead and draw out our lewis structures and see why starting off with our first molecule, we have boron, tri chloride. So we know that Moron is going to give three valence electrons since it's in our group three a. And chlorine is in our group seven A. So we're going to multiply seven by three to get 21 And we'll have to draw out a total of 24 valence electrons drawing this out. We know that boron is going to be our central atom and that's because it's less electro negative than chlorine. And so surrounding our boron with three chlorine. We're going to draw out our seven valence electrons that are chlorine gives and we find that our chlorine does obey the octet rule, but our boron doesn't. And the reason why is because we have 12, 3, 4, 5 and six. We have six valence electrons surrounding our boron when we should have eight. So this would be an incomplete octet. Looking at our next molecule, we have nitrogen dioxide. So we know nitrogen is in our group five a. And oxygen is in our group six a. So six times two is 12. So five plus 12 is going to give us 17 valence electrons drawing this out, nitrogen is going to be our central atom and that's because it's less electro negative than oxygen and we'll have two double bonds connecting our two oxygen's And we know that oxygen is in our group six a. So we'll have two lone pairs surrounding our oxygen's which will get us to those six valence electrons. And for nitrogen, nitrogen is in our group five a. So we'll need to draw a radical electron. Now looking at our structure, we can see that nitrogen is surrounded by and nine. So nitrogen is surrounded by nine valence electrons. So the reason why this doesn't obey our octet rule is because we have an expanded octet. And lastly looking at our last molecule, We know that chlorine is going to give seven valence electrons since it's in our group seven a. And oxygen is going to give six since it's in our group six a. So 7-plus 6 is going to get us to a total of 13 valence electrons. Now drawing this out, we know that chlorine and oxygen are going to be bonded together And we have seven valence electrons for chlorine. And for oxygen We have six. So drawing this out we would have to four, five and six. So oxygen is going to have a radical electron as well. So as we can see right here, oxygen is surrounded by 12345, 6, seven. So this too would be an incomplete octet. So I hope this made sense. And let us know if you have any questions