posted by AMY .
I am refreshing on bonding and structure before starting an organic chem class. I am a bit rusty on hybrid orbitals in bonding. Take Methane, CH4, I understand each carbon has an sp3 orbital that overlaps an s orbital on the H to form its 4 bonds. In a CCL4 atom, which is also sp3 hyrbidized each carbon uses an sp3 orbital to bond to each Cl but which orbital of the Cl atom does the carbon orbital overlap?
17Cl is 1s2 2s2 2p6 3s2 3p5 so what does Cl need to complete its octet?
If I am understanding correctly what you are asking, the 3p orbital can only hold 6 electrons and here it has 5 so it needs 1 more to complete its octet? It would accept 1 electron from the carbon?
So the carbon is the one with the hybridized orbitals. The Cl orbitals don't get hybridized and since the 3p orbital can accept 1 more electron that is the orbital that overlaps with the sp3 of the carbon?
yes. Although I wouldn't go so far as to say the chlorine ACCEPTS an electron from the carbon. I would prefer to say that one electron from the Cl and 1 from the C were shared to form a C:Cl covalent bond. The bond will be somewhat polar because of the difference in electronegativity of C and Cl. Of course 4 Cl atoms do this with the 4 available electrons of C to form the CCl4 molecule. The C atom has a tetrahedral structure because of the sp3 hybridized orbitals with the 4 Cl atoms hanging on at the four corners of the tetrahedran with covalent bonds. By the way, I'm sure you understand that each C-Cl bond is slightly polar but the CCl4 molecule as a whole does not have a dipole moment because it is symmetrical. That is, the individual dipole moments of the 4 C-Cl bonds cancel each other because of symmetry in space. Thanks for using Jiskha.