Chap 6: Chemical bonding II Flashcards
What is hybridization, its characteristics and use.
Hybridization is a mathematical process of combining different atomic orbitals of central atom to produce new orbitals for that central atom.
- hybridization orbitals are only for the central atom
- determine shapes of molecule
- the type of hybridization adapted by the central molecule represents the lowest energy
Valency bond theory introduced hybridization to overcome its deficiencies.
Valency bond theory and its exceptions
that Chemical bonding is a result of overlap of half-filled atomic orbitals that contain valency electrons
Exception
- carbon. it suggests two connections yet we have 4
- water. it suggests a bond angle of 90 yet greater than 90 (bent)
Sigma bonds
Bonds formed from end-to-end overlap of orbitals.
What is internal rotation
Rotation of one end relative to the other end.
around sigma bonds rotation easy, but around double or triple bonds rotation is not easy
What is a double bond
a combination of a sigma bond and a pi bond.
What is a trippble bond
a combination of a sigma bond and two pi bonds.
What is bonding molecular oribital
when electrons in orbtital of two combining atoms combine constructively and reside btn atoms and the energy is lowered
antibonding molecular orbital
when electrons in orbtital of two combining atoms combine destructively and reside btn atoms and the energy of the molecular orbital gets high (unfavore)
Mathematical combinations for hybridizations
Sp2: 33% s-orbitals, and 2 p-orbtials make up 67%
sp3: 25% s-orbtials, and 3 p-orbitals make up 75%
sp
sp3d can be seen as a mixture of two hybridizations: 3 sp2 for equatorial: 33% s and 67%p, and p-d as axial:50% p and d.
sp3d2: - 16.7% s, 50% p, and 33.3%d
What are degenerate MOs? Draw end-to-end and side-to-side bonding and anti-bonding p-orbitals
two pi 2p orbitals have the same energy, and the two pi 2p* also have the same energy.
Delocalized meaning
spread over the entire molecule.
