Hybridization College Chemistry

VSEPR Theory How can I tell what molecular shape an atom is? Geometry not considering lone pairs Geometry considering lone pairs How many single bonds off the central atom?

VSEPR Theory How can I tell what molecular shape an atom is? Dashed line means these electrons are away from you Wedged line means these electrons are towards you

VSEPR Theory How can I tell what molecular shape an atom is? Bond Angle

VSEPR Theory Let’s try methane (CH4) Central atom? Valence Electrons? Draw Bonds? Lone pairs off central atom? none Molecular Geometry? tetrahedral Bond angle? 109.5

VSEPR Theory So let’s try ammonia(NH3) Central atom? Valence Electrons? 5 Draw Bonds? Lone pairs off central atom? One pair Molecular Geometry? Trigonal pyramidal Bond angle? 107

VSEPR Theory Remember those double and triple bonds? We can draw those in VSEPR theory too Only the first bond is counted for bonding purposes (i.e.: a double and triple bond is counted only once) The first bond/single bond – sigma bond (s) Second/third bond – pi bond (p)

VSEPR Theory Remember those double and triple bonds? Let’s try CO2 Central atom? C Valence Electrons? C – 4 Draw Bonds? Lone pairs off central atom? none Molecular Geometry? linear Bond angle? 180 sigma pi

Hybridization Hydridization – mix of several atomic orbitals (s and p subshells) to form hybrid oribals Describes the type of bonds formed, which the VSEPR theory CANNOT do!!

8.3 Hybridization In methane, each of the four sp3 hybrid orbitals of carbon overlaps with a 1s orbital of hydrogen.

Hybrid Orbitals 8.3 Hybridization Involving Double Bonds In an ethene molecule, two sp2 hybrid orbitals from each carbon overlap with a 1s orbital of hydrogen to form a sigma bond. The other sp2 orbitals overlap to form a carbon–carbon sigma bond. The p atomic orbitals overlap to form a pi bond. Inferring What region of space does the pi bond occupy relative to the carbon atoms?

Hybrid Orbitals 8.3 Hybridization Involving Triple Bonds In an ethyne molecule, one sp hybrid orbital from each carbon overlaps with a 1s orbital of hydrogen to form a sigma bond. The other sp hybrid orbital of each carbon overlaps to form a carbon–carbon sigma bond. The two p atomic orbitals from each carbon also overlap. Interpreting Diagrams How many pi bonds are formed in an ethyne molecule?

Hybrid Orbitals sp3 – four things “attached” to central atom sp2 - three things attached, double bonds sp - two things attached, triple bonds Let’s try some…. sp3 sp sp

Hybrid Orbitals A few more… sp2 sp