Transcript week12 - Bryn Mawr College

Isomers, Lewis Structures,
Connectivity and Sigma Bonds
Breathalyzer Test for Ethanol
(Investigate This 5.1)
H2SO4
CH3CH2OH
+ Cr2O7
2-
orange
Quick Time™a nd a
TIFF ( and
LZW) d ecomp
Quic kTime™
a res sor
ar e nee ded to see this pictur e.
TIFF (LZW) decompress or
are needed to see this pic ture.
H3C
+ H2O
H
+
Cr 3+
green
unbalanced rxn
Quic kT i me™ and a
T IFF (LZW) dec om pres s or
are needed t o s ee thi s pi c ture.
before rxn
QuickTi me™ and a
T IFF (LZW ) decompressor
are needed to see t his pict ure.
after rxn
with ethanol
Does Rxn Work For Other
Alcohols (5.1)?
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
n-butanol
iso-butanol
C4H10O
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
sec-butanol
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
tert-butanol
Breathalyzer® Reagent Before
Adding Alcohols (5.1)
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Results of Breathalyzer® Tests
on Various Alcohols (5.1)
ethanol
sec-butyl alcohol
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
n-butyl alcohol
tert-butyl alcohol
iso-butyl alcohol
blank
(acetone only)
Connectivity Matters:
Rxn Does Not Work with tert-Butanol
H2SO4
General Rxn:
Quic kTime™ and a
(LZW) decompress or
R2CHOH + Cr2O7 2-areTIFF
needed to see this pic ture.
QuickTime™ and a
QuickTime™
and a
TIFF (LZW)
decompressor
TIFF (LZW)
are needed
to seedecompressor
this picture.
are needed to see this picture.
tert-butanol
unbalanced
=
+
H2O
+
Cr 3+
R2CHOH (no H is directly bound to the hydroxyl C)
Molecular Orbital Theory

e- in atoms exist in quantized E states
 atomic orbitals (AOs)

e- in molecules exist in quantized E states
 molecular orbitals(MOs)

MOs form from combination of AOs and
belong to molecule as a whole
Forming MOs

e- in AO is a wave

e- waves from two different AOs can interfere



constructive (waves added)
destructive (waves subtracted)
result of interference = two MOs
Forming H2 MOs from H AOs
s* is higher E than AOs
s is lower E than AOs
one AO from each H atom
H
H
two MOs of H2 Molecule
H-H
MO Energy Level Diagram
(“MO Diagram”) for H2
No e- ‘occupies’ this
s orbital.
The bonding e- pair
‘occupies’ this s orbital
H2 forms because e-’s are at lower E
in MOs vs the parent AOs