Is XeF4 violating the octet rule?

  • Thread starter scott_alexsk
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In summary, the octet rule is not violated in the second period elements, but beryllium and boron may bond with more than 8 electrons. The superoxide radical, found in biological systems, also has an extra electron. However, quantum calculations show that the octet configuration is stable due to potential energy minima. Oxygen does not form O8 due to steric strain. Boranes do not satisfy octets and have their own set of rules. XeF4 follows the octet rule when drawn correctly.
  • #1
scott_alexsk
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Is there any violation of the octet rule in the second period elements?
-scott
 
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  • #2
Yes, beryllium typically bonds with 4 electrons (ie BeF2) and boron with 6 (BF3). Flourine is often involved in bonds that have more than 8 electrons (XeF4).
 
  • #3
Also the superoxide radical, O2 with an extra electron. It's found in biological systems.
 
  • #4
movies said:
Also the superoxide radical, O2 with an extra electron. It's found in biological systems.

Just to add, this is a biradical, with an unpaired electron on each oxygen atom.

~H
 
  • #5
Hootenanny said:
Just to add, this is a biradical, with an unpaired electron on each oxygen atom.

~H

You mean singlet oxygen? That's different. In that case you haven't added an electron, in superoxide you have one more electron than you do in the regular oxygen molecule.

Anyway, I think that I was wrong. You can draw a Lewis structure for superoxide radical where you have 3 lone pairs on one O and two lone pairs plus one electron on the other, with a bond between the two. In that resonance structure it's not an octet rule violation. My mistake.
 
  • #6
What about S8?
-scott
 
  • #7
scott_alexsk said:
What about S8?
-scott

S is in the 3rd period...

Also, S8 is a ring of sulfur atoms, so there is no violation.
 
  • #8
Why is octet configuration stable?
 
  • #9
It just is.

Careful quantum calculations show that there is a deep local minimum of the potential energy for filled ns and np subshells. There are also shallow local minima at half-filled subshells. These are just the results of very complex calculations and it's hard to simplify things - in my opinion - to any considerable extent without being "a little" dishonest.
 
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  • #10
Nitrogen does interesting stuff as well - like in hydrazine
 
  • #11
Gokul43201 said:
It just is.

Careful quantum calculations show that there is a deep local minimum of the potential energy for filled ns and np subshells. There are also shallow local minima at half-filled subshells. These are just the results of very complex calculations and it's hard to simplify things - in my opinion - to any considerable extent without being "a little" dishonest.
thanks Gokul
I would request you to explain the difference between a wave and a particle? How would you describe the behaviour of an electron as a wave(qualitatively)?
 
  • #12
Malay, this question is fairly unrelated to the rest of this thread.

I have a couple of suggestions for you.

1. Read post #3 in the Physics FAQ thread : https://www.physicsforums.com/showthread.php?t=104715
It does not directly answer your question, but addresses some part of it.

2. If you still have something you want to ask, start a new thread in the appropriate Physics subforum - General Physics will work - and ask your question there.
 
  • #13
Gokul43201 said:
Malay, this question is fairly unrelated to the rest of this thread.

I have a couple of suggestions for you.

1. Read post #3 in the Physics FAQ thread : https://www.physicsforums.com/showthread.php?t=104715
It does not directly answer your question, but addresses some part of it.

2. If you still have something you want to ask, start a new thread in the appropriate Physics subforum - General Physics will work - and ask your question there.
Thanks for your help
 
  • #14
Why does oxygen not form o8, since it is in the same family as sulfur?Also what about the Boranes?
 
  • #15
One reason is the steric strain. Larger atoms like S, Se, Te can more easily accommodate non-ideal bond angles that are necessary to make the ring structures.

What about the boranes? Yes, they do not satisfy octets in general (see post#2, by cesium). Also look into Wade's rules for constructing boranes with n electron pairs.
 
  • #16
Does that mean that XeF4 follows the octet rule?
 
  • #17
try and draw out the structure of XeF4 and count the electrons. If you draw the correct structure your question should be answered.
 

1. 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 outer electron shell with eight electrons, similar to the noble gases.

2. What is a violation of the octet rule?

A violation of the octet rule occurs when an atom has an electron configuration that does not follow the typical pattern of eight valence electrons in its outer shell. This can happen in certain molecules or ions due to the presence of an odd number of valence electrons or atoms with more than eight valence electrons.

3. What are some examples of violations of the octet rule?

Some examples of violations of the octet rule include molecules like boron trifluoride (BF3), which has only six valence electrons around the central boron atom, and sulfur hexafluoride (SF6), which has 12 valence electrons around the central sulfur atom.

4. What are the consequences of a violation of the octet rule?

A violation of the octet rule can result in molecules or ions with unusual properties, such as being highly reactive or having a distorted molecular shape. This can also affect the stability and reactivity of the compound, as well as its ability to form chemical bonds with other substances.

5. Can the octet rule be violated in all molecules?

No, the octet rule is not always violated in molecules. It is a general guideline based on observations, and there are exceptions to the rule. For example, molecules with an expanded octet, such as phosphorus pentachloride (PCl5) and sulfur hexafluoride (SF6), can still follow the octet rule while having more than eight valence electrons in their outer shells.

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