How is the hybridization type determined in relation to VSEPR theory?

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Determining hybridization involves counting the regions of electron density around an atom, which includes single bonds, double bonds, triple bonds, and lone pairs. The general rules state that two regions correspond to sp hybridization, three regions to sp2, and four regions to sp3. While these rules primarily apply to carbon and can also be used for nitrogen by considering lone pairs as bonding regions, they are not universally applicable to all elements. The discussion highlights the importance of drawing Lewis structures to accurately assess the number of electron regions. Additionally, there are debates regarding specific molecules like BeCl2 and ClO4, with some participants questioning the validity of certain hybridization assignments based on molecular geometry and bond angles. The conversation also touches on the outdated notion of d orbital involvement in hybridization for main group elements.
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How could I know the hybridization type in such a question
 
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How do you determine hybridization in general?
 
If the atom have one bond with another, the hybridization type is SP3. If it's double-bonded, the hybridization type is SP2. If it's triple-bonded with another one, the hybridization type is SP.
Can I use this in less general cases?
 
I find that the simplest approach to determine hybridization is just to count the number of regions containing electrons. To clarify what I mean, a single bond, a lone pair, a double bond, a triple bond etc would each count as one. It helps to draw lewis structures of each compound, that way you can make sure you get the right number of lone pairs.

After you know the number of regions containing electrons, you know the hybridization! Just use the table below.

2 regions = sp
3 regions = sp2
4 regions = sp3
 
Borek said:
Thats true only for carbon, it is not a general approach. Many ways to skin that cat, see for example http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch8/hybrid.html

ZacharyM said:
I find that the simplest approach to determine hybridization is just to count the number of regions containing electrons. To clarify what I mean, a single bond, a lone pair, a double bond, a triple bond etc would each count as one. It helps to draw lewis structures of each compound, that way you can make sure you get the right number of lone pairs.

After you know the number of regions containing electrons, you know the hybridization! Just use the table below.

2 regions = sp
3 regions = sp2
4 regions = sp3

Thanks all, that was so useful. obviously letter B is the right answer
 
Why not also E?
Is BeCl2 in the gas phase or solid?
Does neutral ClO4 really exist?
I wonder who poses these brain dead exercises?
 
DrDu said:
Why not also E?
Is BeCl2 in the gas phase or solid?
Does neutral ClO4 really exist?
I wonder who poses these brain dead exercises?

In E. hybridization type is sp3 in NH3 & it is sp2 in SO2 so it is wrong
If BeCl2 is gas or solid, I don't think there would be a difference in the answer
ClO4, I think it is so hard for such a molecule to be found
 
You can argue that in SO2 S is also sp3 hybridized and that the somewhat larger bond angle is due to electrostatic repulslion of the oxygens. So you can equally well describe it with sp2 or sp3.
In the case of BeCl2, which is a solid at room temperature, Be is coordinated by 4 Cl atoms, so that a sp3 hybridization is also most natural.
 
  • #10
Step 1: Count the number of bonding regions on the atom in question plus the number of unshared pairs of electrons.

Step 2: Beginning with the s orbital and working your way up, keep adding orbitals to the hybridization until the superscripts add to the number of bonding regions.

Ex. for methane, carbon has 4 bonding areas. Add the s orbital which gives you 1, and then all three p orbitals for 3, so you have sp3 hybridization.

Ex.2 For ammonia, you have 3 bonding areas, plus an unshared pair on the Nitrogen, so again, it is sp3.

Ex.3 For PCl5, the phosphorous has 5 bonding areas of electrons and 0 unshared pairs, so you add in the s orbital, 3 p orbitals, and 1 of the d orbitals for sp3d orbital.
 
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  • #11
Ammar Qasim said:
If the atom have one bond with another, the hybridization type is SP3. If it's double-bonded, the hybridization type is SP2. If it's triple-bonded with another one, the hybridization type is SP.
Can I use this in less general cases?

For carbon you can use this as a general rule. You can also use it for Nitrogen if you consider its unshared pair a bond.
 
  • #12
These rules are more a variant of VSEPR theory.
epsaliba said:
Ex.3 For PCl5, the phosphorous has 5 bonding areas of electrons and 0 unshared pairs, so you add in the s orbital, 3 p orbitals, and 1 of the d orbitals for sp3d orbital.
Involution of d orbitals in main group elements has been disprooven since at least 50 years ago!
 
  • #13
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