In HCN, what is the hybridization of the sigma bond bw the C and N? The answer is sp.
I don't understand "hybridization of the sigma bond"? How does this differ from hybridization of the atom... and why is the answer sp?
A triple bond is made of 1 Sigma and 2 Pi bonds;
in regards to valence bond theory (orbital mixing), we hypothetically mix
1s orbital and 3 p orbitals to get= 4 equivalent sp3 orbitals (for alkanes)
1s orbital and 2 p orbitals to get =3 equivalent sp2 orbitals (alkenes)
^the P orbital that wasn't hybridized is left over, and when it overlaps with another p orbital you get a pi bond
so, for alkynes, C-C triple bonds, the sigma bond is sp hybridized because only an 1s orbital and 1 p orbital hybridize to give 2 equivalent sp orbitals; this sp orbital makes the SIGMA bond; the two 2 orbitals that weren't hybridized give the pi bonds.
it is the UNHYBRIDIZED P orbitals that make up the Pi bonds; the hybridized p orbitals that "mix" with the s orbital make the sigma bond, and hence, for alkynes, only an S and P orbital mix so the sigma bond is sp hybridized.
