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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: sharbeldam on December 01, 2020, 05:31:50 AM

Title: Does this hybridization general rule apply?
Post by: sharbeldam on December 01, 2020, 05:31:50 AM
So this rule is known about hybridization that:
if 4 groups (atoms/pairs of electrons) are around the atom -> sp3
if 3 -> sp2
if 2 -> sp

but isn't that true only to specific elements only like carbon/oxygen/nitrogen..?

If you take CCl4, C is sp3, but chlorine has 4 groups around it but it's still not sp3 nor hybridized, it's just an sp3-p bond.

Even for nitrogen like in pyrrole, nirogen has 4 groups around it but it's sp2 because of resonance.


but can someone make it clear? to which elements does that rule apply? what elements undergo hybridization? what elements can they ask about in college regarding that?

Thank you
Title: Re: Does this hybridization general rule apply?
Post by: Borek on December 01, 2020, 08:34:19 AM
If you take CCl4 (...) chlorine has 4 groups around it

Does it?
Title: Re: Does this hybridization general rule apply?
Post by: Babcock_Hall on December 01, 2020, 10:08:27 AM
@OP, Are you referring to steric number when you talk about groups?

I agree that resonance delocalization adds some complexity.  Offhand, I would say that one has to examine all major resonance forms when thinking about the hybridization of an atom.
Title: Re: Does this hybridization general rule apply?
Post by: sharbeldam on December 01, 2020, 05:02:25 PM
group is atom/pair of electrons so yes Cl is CCl4, has 4 groups meaning 3 pairs and atom attached.

basically what im asking is for instance when i have
C-Cl
the bond is SP3-P
but if you take the rule that i put in my initial post , the student would put
SP3-SP3

If I had HC[triple bond]N:

It would be S-SP-SP
because Nitrogen somehow can be hybridized unlike Cl even when it's an outer atom, it's a bit confusing when that rule apply and when it doesnt to outer atoms...
Title: Re: Does this hybridization general rule apply?
Post by: Babcock_Hall on December 01, 2020, 05:56:01 PM
Why do you say that Cl must use a p orbital in its bond to carbon?  In other words why can't it be sp3?
Title: Re: Does this hybridization general rule apply?
Post by: sharbeldam on December 02, 2020, 01:51:04 AM
Why do you say that Cl must use a p orbital in its bond to carbon?  In other words why can't it be sp3?

Does it? Im truly so confused now, a professor said it's sp3-p, cause hybridization is only for the central atom, whilst the outer atoms just use its normal orbital. so the rule in the original post apply for  outer atoms too?

Title: Re: Does this hybridization general rule apply?
Post by: AWK on December 02, 2020, 04:08:58 AM
It all depends on the level of chemistry. This is enough for general chemistry. But very often students start to believe that this is an absolute truth.
http://www.colby.edu/chemistry/webmo/CCl4.html