Class notes CHEM 121: Chapter 9

Chapter 9: Valence Bond Theory




1) (x ) I 2022

, valence Bond Theory,vBi)
molecule
-identify 5 or bonds in a given
~
relate this to USEPR

~
Hybridization


Bond forms due to overlap

↳ Sigma bond


↳ X2 pi bond



· Each covalent bond like an idependant species

↳) treat each covalent bond as an independant interaction

↳) only consider paramagnetic species in this chapter

↳> don't think about
antibonding, bonding here




Orbitals in UBT and MO theory have the same shape no: molecular orbital

but are labelled DIFFERENTLY

NO: O IS
example:
VBT:5 (Is-1s) write which cribals have overlapped




orbitals enough
Hetero nuclear: that are close in
energy

dash like
different colors represents
that

represent bonding theve
was nO


over 10p
-
T(Gp2-Gp2)




· (py -<py)
/VBT notation)


TCGp2 -2pn)




2

2 BI

steps on how to drow valence bond diagram:

1 write types of atom
2P4

2. draw orbitals /2s, <p) X


↳) draw is line lower than 2p
CP2L
3. Fill lower energy orbitals first
2
4 satisfy nunds rule still all P orbital first 1)
key Ideas

· one bond will Always bonds
be sigma rest will be pi




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