Understanding Octet Rule for NO2 and ClO-

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In summary, the conversation discusses the octet rule and whether NO2 and ClO- obey it. It is concluded that NO2 obeys the octet rule due to its resonance hybrid structure, while there is some uncertainty about ClO-. The existence of N2O4 is also mentioned as an example of how the octet rule can be broken. It is noted that nitrogen usually has three bonds and does not form compounds with only 3 bonds.
  • #1
a.a
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Does NO2 obey the octet rule? I know NO2 + does so I figured that NO2 wouldn't I can't figure out how to draw NO2 using formal charges.

Does ClO- obey the rule? I tried drawing it and I think it does but I am not 100% sure
 
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  • #2
NO2 obeys, but I'm not sure about ClO-, so I won't add to the confusion on that one.

NO2 exists as a resonance hybrid; that is, one double bond is shared between the two N-O bonds. Because of this, the oxygens get 2 bonds most of the time (making them neutral) while nitrogen gets 3 bonds most of the time (making it neutral). This picture shows the hybrid (the dotted lines imply sharing of the double bond):
http://en.wikipedia.org/wiki/Image:Nitrogen-dioxide-2D-dimensions.png" [Broken]
 
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  • #3
Cl-O- obeys the octet rule. You can think of it like HO-, aka hydroxide, except hydrogen has been replaced with chlorine. Then add lone pairs of course to make chlorine neutral and have a complete octet.
 
  • #4
Nitrogen-dioxide-2D-dimensions.png


if the dotted lines represent 'half bonds' then the nitrogen would indeed have 3 bonds but each oxygen atom only has 1 1/2 bonds. shouldn't there be another dotted line between the 2 oxygen atoms?
 
  • #5
No, the N in NO2 does not obey the octet rule (rules are there to be broken). Neither does N in NO. In the liquid phase (that is somewhere below 4 deg Celsius if I remember correctly). NO2 actually prevails as N2O4 which obeys the octet rule. The bond between the two N's is very weak, however. This is a general feature of the homopolar bonds at the end of the period. E.g., the bond in F2 is also very weak. The problem is that the elements at the end of the period are so crammed up with electrons, that electron repulsion couteracts bond formation.
 
  • #6
280px-Stickstoffdioxid.svg.png


but the nitrogen always has 3 bonds. How could there be a N-N bond?
 
  • #7
He's talking about the N-N bond in N2O4
 
  • #8
so am I

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ImagesHandler.ashx?id=4574075.png
 
  • #9
The upper of the two formulas is the one I am talking about.
Nitrogen does not form compounds with 3 bonds, only. Think of
The Ammonium ion NH_4+, Nitrylchloride NO_2Cl or Nitrylfluoride NO_2F.
 
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What is the octet rule?

The octet rule is a chemical principle that states that atoms tend to gain, lose, or share electrons in order to achieve a stable electron configuration with 8 valence electrons.

How does the octet rule apply to NO2 and ClO-?

In NO2, nitrogen has 5 valence electrons and needs 3 more to achieve an octet. It can either gain one electron to form NO2- or share 2 electrons through a double bond to form NO2. In ClO-, chlorine has 7 valence electrons and needs one more to achieve an octet. It can gain an electron to form ClO- or share an electron through a single bond to form ClO.

Why do some molecules not follow the octet rule?

The octet rule is a general guideline and not a strict rule. Some molecules, such as those with an odd number of valence electrons or those with expanded valence shells, do not follow the octet rule.

What happens if an atom has more than 8 valence electrons?

Atoms in period 3 or higher on the periodic table can have expanded valence shells, meaning they can have more than 8 valence electrons. This is because these atoms have access to d orbitals, which can accommodate additional electrons.

Can molecules have less than 8 valence electrons?

Yes, some molecules can have less than 8 valence electrons and still be stable. Examples include beryllium and boron compounds, which can have 4 and 6 valence electrons, respectively.

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