LM25-26 Flashcards
Sigma bonds form where in relation to axis?
the axis between two atoms
Pi bonds form where in relation to axis?
off the axis between two atoms
A chemical bond/molecular orbital is
an overlap of electron dense regions between two atomic orbitals
VB Theory tells us
locations of every valence electron and a visual representation of atomic orbitals
A covalent bond is
the force that attracts shared electron pairs to the two opposite nuclei
The strength of a covalent bond is proportional to
the extent of overlapping of atomic orbitals
Molecular orbital is
the result of shared electrons between overlapping atomic orbitals
s orbitals always create (explanation)
sigma bonds, spherical electron rich region always aligns with the inter-nuclear axis
p orbitals that do not overlap head on create
pi bonds
Sideways overlap corresponds to
pi bonds
Head-on overlap corresponds to
sigma bonds
How many orientations of p orbitals can form pi bonds?
2
Single bond is what type of bond
Sigma
Double bonds include what types of bonds
1 sigma and 1 pi
Triple bonds include what types of bonds
1 sigma and 2 pi
Resonance includes what types of bonds
1 sigma and a fraction of a pi bond
Hybrid Orbitals
a mixture of s, p, or d orbitals
How many possible hybrid orbitals are there?
5: sp, sp2, sp3, dsp3, d2sp3
The number of hybrid orbitals corresponds with
number of electronic geometries/e rich regions
Hybrid orbitals can only form (explanation)
Sigma bonds, all hybrids have s character
Why is methane hybridized?
There is only 1 spectral peak for the 4 equivalent C-H bonds, indicating they are all the same because of hybridization
sp hybridization (number of e- rich regions, shape)
2 electron dense regions, linear
sp2 hybridization (number of e- rich regions, shape)
3 electron dense regions, trigonal planar
sp3 hybridization (number of e- rich regions, shape)
4 electron dense regions, tetrahedral
dsp3 and d2sp3 only appear in atoms that are
hypervalent (d orbitals, n=3)
dsp3 hybridization (number of e- rich regions, shape)
5 electron rich regions, trigonal bipyramidal
d2sp3 hybridization (number of e- rich regions, shape)
6 electron rich regions, octahedral
As bond length decreases, bond energy
increases
Molecular orbitals correspond to
types of bonds
Atomic orbitals correspond to
types of orbitals + hybrids
Which hybrid typically doesn’t form pi bonds
sp3
