a. Predict the relative bond lengths of the three carbon–oxygen b...

Question

a. Predict the relative bond lengths of the three carbon–oxygen bonds in the carbonate ion. b. What is the charge on each oxygen?

Accepted Answer

Hey, everyone, let's do this problem and says the structure of the nitrate ion is given below a predict the relative bond length of each bond. And b what is the charge on each oxygen atom? So we can't just consider this one nitrate ion structure given to us because the nitrate ion has a few different resonance forms. And we know that with resonance, the structure is sort of continuously moving fluidly between these different structures, right. So it's almost like it's all of the structures at once. So we have to consider all of the residents structures for the nitrate ion. So let's draw those out. So we have this negative oxygen, we'll take that lone pair, swing it down towards the positive nitrogen, breaking this double bond on the other oxygen. So we're transferring that negative charge on the oxygen to that top oxygen. Now, we have our double bond oxygen in the bottom left corner, our bottom right hand oxygen is still negative as well and our nitrogen still has a positive charge and we can have one more resident structure where the lone pair from that bottom, right. Oxygen does the same thing forms a double bond breaking that double bond we just formed. So now our bottom right oxygen is double bonded to the nitrogen. Bottom, left oxygen has a negative charge again, and our nitrogen still has a positive charge. So those are our three resonance forms. And we also want to consider the hybrid structure which as I said for resonance, all of these structures are sort of happening at the same time. So we can represent this concept by a hybrid form. So to draw a hybrid draw all the single bonds first. Okay. Now any place where there was a double bond, draw a dotted line and we see that there's a double bond between every oxygen atom in our resonance structures. So for each nitrogen oxygen bond draw a dotted line and now we add the charges, we have a positive charge on our nitrogen in every structure. So the nitrogen gets a positive charge for our oxygen. It doesn't always have a negative charge, right? But there's at least one structure where each oxygen has a negative charge actually in each, in two of each structure, a certain oxygen animal have a negative charge. So each oxygen atom will get a partial negative charge. Okay. So now with all this information, I think we can more easily answer the two questions. So a predict the relative bond length of each bond. So we know that the bond length relates to the number of Covalin bonds, right? The more Covalin bonds, we have the shorter the bond length. So a triple bond will be the shortest bond length. A single bond will be the longest bond length. But as we can see in the resonance hybrid structure, each nitrogen oxygen bond will have the same double bond character, right? So resonance hybrid shows same double bond character for all the nitrogen oxygen bonds. So the relative bond length of each nitrogen oxygen bond, it's all the same, all three nitrogen oxygen bonds have the same bond length. Alright. Part B asks, what is the charge on each oxygen atom? So again, sort of looking at that resonance hybrid structure, all of the negative charges on the oxygen's are going to be the same, just like all the bond lengths are going to be the same because those electrons are constantly moving between these three structures and all those resonance structures are equal contributors. So each oxygen carries, we can't really give it a definite charge like a like a negative one, right? Because it's moving around. So we'll just say each oxygen carries the same amount of partial negative charge. So those are the answers for this problem which makes choice a the correct choice. That's it for this one. I hope this video is helpful and thanks for watching.

a. Predict the relative bond lengths of the three carbon–oxygen bonds in the carbonate ion. b. What is the charge on each oxygen?

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