3d and 4s orbital (PCl5)
We know that P is in the third period. There are some 3d orbitals.
and we know that 4s orbital is lower energy level than 3d when they are empty.
The hybrid orbital of P in PCl5 is sp3d orbital.
That means P use the 2s, 2p ,3d orbital for hybridization and not use the 4s orbital for hybridization.
but why?
Why do the hybrid orbital not sp3s (2s, 2p ,4s) orbital?
3d and 4s orbital (PCl5)
2007-07-17 1:49 am
回答 (2)
2007-07-17 7:22 am
✔ 最佳答案
It is very difficult to explain this in A-level. Your teacher may just say that you should remember this.I understand your question. I also had this question when I was in F.6.
You may know that in order to form PCl5, one of the electron in s orbital of P need to be promoted to 3d but not 4s to form 2 extra covalent bonds. Why not 4s?!
The main reason is that 4s is much distant to 3p and 3s as compared to 3d. If 4s really get involved, the total potential energy of the hybrid orbitals "sp3s" would be increased such that it is unlikely to form.
In other words, sp3d orbitals would have lower energy level and more stable. So, less energy is requried to make it!!
圖片參考：http://hk.yimg.com/i/icon/16/41.gif
參考: ME
2007-07-31 3:36 am
It is very difficult to explain this in A-level. Your teacher may just say that you should remember this.
I understand your question. I also had this question when I was in F.6.
You may know that in order to form PCl5, one of the electron in s orbital of P need to be promoted to 3d but not 4s to form 2 extra covalent bonds. Why not 4s?!
The main reason is that 4s is much distant to 3p and 3s as compared to 3d. If 4s really get involved, the total potential energy of the hybrid orbitals "sp3s" would be increased such that it is unlikely to form.
In other words, sp3d orbitals would have lower energy level and more stable. So, less energy is requried to make it!!
I understand your question. I also had this question when I was in F.6.
You may know that in order to form PCl5, one of the electron in s orbital of P need to be promoted to 3d but not 4s to form 2 extra covalent bonds. Why not 4s?!
The main reason is that 4s is much distant to 3p and 3s as compared to 3d. If 4s really get involved, the total potential energy of the hybrid orbitals "sp3s" would be increased such that it is unlikely to form.
In other words, sp3d orbitals would have lower energy level and more stable. So, less energy is requried to make it!!
參考: me
收錄日期: 2021-04-12 20:10:54
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