(c) What would you predict for the lengths of the bonds in NO 2 - relative to N¬O single bonds and double bonds?

Hello. Everyone in this video we're going to be discussing the bond length of carbon and oxygen atoms given three different molecules. So there's going to be three different kinds of bonds, we have our single bonds, we have our double bonds and of course we have our triple bonds. So our single bonds is going to be the longest and the weakest of our bonds. So longest and weakest and the fair triple bonds is going to be the shortest and it's going to be our strongest of the bonds. And the double bonds just kind of in the middle. It's going to be shorter than are single bond but longer than our triple bond. And it's going to be stronger than are single bond but still weaker than our triple bond. Alright, so let's go ahead and draw the lewis structure for each three of these different molecules. And then we can see what kind of bonds we have. So for a So we have one carbon That's going to give us four valence electrons. And then we have three oxygen's. So three times while oxygen has six valence electrons has three times six point all the inter calculators. We will be getting 24 Or 22 with electrons. But you can see that this is an ion of two minus mean that there's going to be two extra electrons since it's negative. So add to And that would give us valence electrons total. Alright. So for our lower structure then it's going to be carbon Bureau central atom. It's going to have a double bond to one of our oxygen atoms. Any single bond for the others drawn our lone pairs here. All right. So actually, since it is an eye on we have to go ahead and put this in brackets and give a negative two charge. And where does that negative to come from? So on our left side and on the bottom here these two auction items has a negative one. So negative one plus a negative one will give us a negative two charge. Alright, so next for a beat we have our carbon dioxide. So we have one carbon. So it's four valence electrons. And then we have two oxygen's. So two times 6. Now we are going to give us a total of 16 bands electronic But during out the lewis structure, you have carbon again being our central atom. So upon into two oxygen's and of course filling your lone pairs. All right. And lastly we have see we have a carbon monoxide. So we have one carbon. So four valence electrons and we have one oxygen. So one or sorry, six valence electrons Total. Will get a total of 10 valence electrons. All right, joining out the lower structure for this. We have carbon triple bonded To an oxygen. And of course one long pair per atom. All right, so taking a look at all of our lowest structures here, we have double bonds. We have double bonds, single bonds, triple bonds. And we want the longest bond that is going to be our single bonds right here. Right, So the only molecule that displays any type of single bonds is going to be this right here, because this only has double bonds and this one only has triple bonds. Alright, so our correct answer is actually going to be a her eye on. Alright guys, thank you guys so much for watching. Hopefully you found this video helpful and good luck in your studies.

Ch.8 - Basic Concepts of Chemical Bonding

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Brown 14th Edition

Ch.8 - Basic Concepts of Chemical Bonding

Problem 53c

Chapter 8, Problem 53c

(c) What would you predict for the lengths of the bonds in NO₂^- relative to N¬O single bonds and double bonds?

Verified step by step guidance

Understand the structure of the nitrite ion (NO2-). It consists of a nitrogen atom bonded to two oxygen atoms, with one of these bonds being a double bond and the other a single bond, due to resonance.

Recognize that resonance in NO2- means that the actual structure is a hybrid of the two resonance forms, where the double bond and single bond are averaged over the two N-O bonds.

Recall that in resonance structures, the bond lengths are intermediate between the lengths of a single bond and a double bond. This is because the electron density is delocalized over the entire molecule.

Compare the bond lengths: A typical N-O single bond is longer than a typical N-O double bond. Therefore, the bond lengths in NO2- will be shorter than a single bond but longer than a double bond.

Conclude that the bond lengths in NO2- are equal due to resonance and are intermediate between the lengths of a N-O single bond and a N-O double bond.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Bond Order

Bond order is a measure of the number of chemical bonds between a pair of atoms. It is calculated as the difference between the number of bonding electrons and the number of antibonding electrons, divided by two. In the case of nitrogen dioxide (NO2) and its anion (NO2-), the bond order helps predict the bond lengths, as higher bond orders typically correlate with shorter bond lengths due to increased electron density between the bonded atoms.

Resonance Structures

Resonance structures are different ways of drawing the same molecule that illustrate the delocalization of electrons. In NO2-, resonance indicates that the actual structure is a hybrid of these forms, leading to bond lengths that are intermediate between single and double bonds. This concept is crucial for understanding the bond lengths in NO2- as it affects the distribution of electron density and the effective bond order.

Bond Length Trends

Bond length is influenced by the type of bond formed between atoms; single bonds are generally longer than double bonds due to the increased electron sharing in double bonds. In NO2-, the bond lengths can be predicted to be shorter than a typical N-O single bond but longer than a double bond, reflecting the resonance and partial double bond character present in the anion.