Lewis Structure for NO3-

[Alexa Pham 1D]

In Dr. Lavelle's lecture, he went over the Lewis structure of NO3-, the nitrate ion. I'm confused to how both of the single bonded oxygens were able to achieve a full octet, since the "-" in NO3- will only allow the molecule to have one more electron. I hope my question makes sense, it's a bit confusing to explain it.

[Andrew Wang 1C]

Each of the single-bonded oxygens has 3 lone pairs, which combined with the single bond gives them a full 8 electron octet. I'm not sure about the "-" in NO3-, but I hope this helps!

[Kiran Singh 3A]

If I understand your question correctly... the line represents the sharing of electrons, so the line would actually be counted as 2 electrons for each atom. So the O with 2 lone pairs (4 electrons) and a double bond (plus 4 electrons) achieves an octet, and the O with 3 lone pairs (6 electrons) and a single bond (plus 2 electrons) achieves an octet as well. The N achieves an octet too because it is double bonded with one O (4 electrons) and single bonded with two Os (plus 2 electrons plus 2 electrons). Hope this makes sense.

[Emily Ding 1J]

The single bonded oxygens had two electrons from the bond with nitrogen (the line), and then 6 total unpaired electrons drawn as dots. The double bonded oxygen had four electrons from the bonds, and 4 unpaired. If you add up all of the electrons, it matches the expected amount of valence electrons, given that you had to add one due to the negative charge. I hope this made sense!

[Nika Gladkov 1A]

The single bonded oxygens in nitrate were able to have a full octet because of their lone pairs as well as the single covalent bond with the nitrogen. In the lewis structure, the single bonded oxygens all had 3 lone pairs, giving them 6 electrons. Their single bond with nitrogen means that they share 2 electrons with it--these electrons belong to both the oxygens and the nitrogen. These two electrons serve to complete the octet.

Hope that helps!

[Kareena Patel 1G]

Hi!

So the single-bonded oxygens have 6 valence electrons so with the single bond plus the 6 valence electrons, they have 8 electrons all together. I think this image will help the most to visualize it.

[Alexa Pham 1D]

I'm just a bit confused still because in the image, it looks like nitrogen only has 4 valence electrons when it should have 5?

[Alexa Pham 1D]

Also, I don't know if I should apply this but in high school chemistry, I learned that nitrogen can only have 3 bonds. So why is it that the nitrogen in NO3- has 4 bonds?

[Benjamin Chen 1H]

I think it was because of the octet rule.

Or, you can think of the N as N+ so it can form 3 sigma bonds in the sp2 hybridization orbital and 1 pi bond in the remaining p orbital. (this might be completely wrong)

[Emmeline Phu 1G]

Hi! When drawing the lewis structure for NO3-, first start by counting the number of valence electrons. Since NO3- is an anion, add an extra electron to the number of valence electrons meaning there is a total of 24 valence electrons. From there, apply the octet rule to both N and O to ensure that all of them have eight electrons. This gives a result of 1 double bond between N and O to allow N to achieve an octet. Hope this helps! :)

[Alexa Pham 1D]

Thanks guys! I think I understand. Just to clarify, when draw the Lewis structure for NO3-, we have to make sure that the octet for each atom is filled first? I think was focused on how nitrogen can only make 3 bonds so that's why I couldn't quite understand why N has 4 bonds in the Lewis structure for NO3-.