Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: HellFrozenOver on 08/01/2008 15:04:46
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Can anyone help me understand how orbitals are hybridized.. I dont understand exactly how to figure out if an orbital of an atom is sp3, sp2 or sp hybridized.. For example in the case of carbon.. It can be hybridized through all three ways.. CH4 is sp3 hybridized, C2H4 is sp2 hybridized, etc2.. But what makes it that way? And how can i figure out the hybridization of atoms for other molecules?
Thanks
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It's actually pretty easy to calculate the hybridization of an atom. Count the number of things (either atoms, lone pairs or unpaired electrons). This will tell you the number of atomic orbitals that go into making the hybrid orbitals.
1 thing = irrelevant - not hybridized
2 things = 2 orbitals - s + p = sp-hybridized (e.g., C in CO2)
3 things = 3 orbitals - s + p + p = sp2-hybridized (e.g., C in C2H4, S in SO2)
4 things = 4 orbitals - s + p + p + p = sp3-hybridized (e.g., CH4, NH3, H2O)
It is my not-so-humble opinion that hybridization is a useful fiction espoused by organic chemists to explain the very small portion of the periodic table in which they are interested. Hybridization and VSEPR theory tend to fall apart unless you're dealing with a specific set of circumstances that are almost always present in organic molecules, but are often not present in inorganic molecules.
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As I understand it it's really a bit of a fudge based on the physics to explain what might be going on. in theory for example a carbon atom with four orbitals making CH4 there would be 3 bonds to the p level and one to the s level making it a bit different but they can't tell them apart so they say thy are hybridised :-)