1. Sign in Pick up papers Sit with the same group as last week.
Chem 108: Lab Week 8
Sign in
Pick up papers
Sit with the same group as last week. A E C D B

2. Chemical Reactions Combination (Synthesis) Decomposition
Single Displacement
Double Displacement
Combustion: Oxidation-Reduction
Biological Reactions: Enzyme Catalysts
Example: Fermentation
_________________________
A 3900-year-old clay tablet, which was found in Iraq between the Tigris and Euphrates rivers, had a Sumerian poem ( honoring Ninkasi, the patron goddess of brewing. It contains the oldest surviving beer recipe, describing the fermentation of the carbohydrates found in bread, bappir, made from barley, honey, dates and sweet aromatic herbs. The global availability of carbohydrates and native microbes (yeasts) has led to the production of many different types of beers, ales, wines, and fruit based alcoholic beverages in many countries throughout the world. [The bottle on the left was found in Eugene, Oregon, ……. But, it dates only to 2016.]

3. Chemical Reactions Combination (Synthesis) Decomposition
To DO Today
With same fermentation partner; Lab Manual pp.44-45
Combination (Synthesis)
Decomposition
Single Displacement
Double Displacement
Combustion: Oxidation-Reduction
Biological Reactions: Enzyme Catalysts
Example: Fermentation pp.61-67
_________________________
A 3900-year-old clay tablet, which was found in Iraq between the Tigris and Euphrates rivers, had a Sumerian poem ( honoring Ninkasi, the patron goddess of brewing. It contains the oldest surviving beer recipe, describing the fermentation of the carbohydrates found in bread, bappir, made from barley, honey, dates and sweet aromatic herbs. The global availability of carbohydrates and native microbes (yeasts) has led to the production of many different types of beers, ales, wines, and fruit based alcoholic beverages in many countries throughout the world. [The bottle on the left was found in Eugene, Oregon, ……. But, it dates only to 2016.]

4. Molecular Modeling Complete Cover page Today and turn in next week
A 3900-year-old clay tablet, which was found in Iraq between the Tigris and Euphrates rivers, had a Sumerian poem ( honoring Ninkasi, the patron goddess of brewing. It contains the oldest surviving beer recipe, describing the fermentation of the carbohydrates found in bread, bappir, made from barley, honey, dates and sweet aromatic herbs. The global availability of carbohydrates and native microbes (yeasts) has led to the production of many different types of beers, ales, wines, and fruit based alcoholic beverages in many countries throughout the world. [The bottle on the left was found in Eugene, Oregon, ……. But, it dates only to 2016.]

5. Molecular Modeling Computational Chemistry
Covalent Bonds: Lewis Structures, Molecular Shapes
Dr. Ron Rusay

6. Molecular Modeling Computational Chemistry
Shapes Lewis Structures
Polarity, Solubility, Stereochemistry
Smell, Teratogenicity
Dr. Ron Rusay

7. Shapes of Molecules https://www.youtube.com/watch?v=Jq_Ca-HKh1g
View: What is the shape of a molecule? George Zaidan and Charles Morton

8. Molecular Shapes Molecular Models for C, H, N, O
Fundamental repeating shapes found in every biological molecule
C =black
H = gray
N = blue
O = red
pink = generic atom

9. Photo Bancroft Library, University of California/LBNL Image Library
Professor Gilbert Newton Lewis (circa 1940)
Notes from Lewis’s notebook
and his “Lewis” structure.
G.N. Lewis
Photo Bancroft Library, University of California/LBNL Image Library
Footnote:
G.N. Lewis, despite his insight and contributions to chemistry, was never awarded the Nobel prize.

10. Valence Electrons – Lewis Dot Drawings
A Groups-Periods 2 & 3 .H

11. Covalent Bond Numbers .H one bond two bonds three bonds four bonds
(Neutral Atoms!) .H
one bond H F Cl Br I O
two bonds N
three bonds C
four bonds

12. (Handout)
Due End of Lab Next Week

13. Lewis Structures Molecular Shapes
For simple Lewis structures:
Draw the individual atoms using dots to represent the valence electrons.
Put the atoms together so they share PAIRS of electrons to make complete octets.
NH3, for example:
Eg. Ammonia:

14.
Molecular Shapes Lewis Structures MolView: Visual On-line Molecular Modeling
Bonding, Lewis Structures, Molecular Modeling: Computational Experiments, Instructions, & Manual pp

15. (Course/ Lab Manual pp. 53-58) Organize Today with your Moleview Group
(Course/ Lab Manual pp ) Organize Today with your Moleview Group
Due End of Lab Next Week

16. Orbital (Electronic)
Geometry
Molecular
Geometry
Bond Angle
# of lone pairs
Important in
Organic
Compounds
Linear Linear
Trigonal Planar Trigonal Planar
Trigonal Planar Bent
Tetrahedral Tetrahedral
Tetrahedral Trigonal Pyramidal
Tetrahedral Bent
Trigonal Bipyramidal Trigonal Bipyramidal
Trigonal Bipyramidal Seesaw
Trigonal Bipyramidal T-shape
Trigonal Bipyramidal Linear
Octahedral Octahedral
Octahedral Square Pyramidal
Octahedral Square Planar 1 2 3
See again in
Chem 120
and possibly in
Chem 109

18. Covalent Compounds Share valence electrons.
1 pair = 1 bond; maximum # of atom-atom bonds = 3.
Octet rule (“duet” for hydrogen)
Lewis structure examples:
Notice the charges:
In one case they balance, can you name the compound?
In the other they do not.
It has a “Formal” charge. Can you name the polyatomic ion?

19. Molecular Shapes Lewis Structures MolView: Polyatomic Ions
Molecular Shapes Lewis Structures MolView: Polyatomic Ions
Bonding, Lewis Structures, Molecular Modeling:

20. Resonance
Occurs when more than one valid Lewis structure can be written for a particular molecule. [Adjacent free electrons, double or triple bonds.]
These are resonance structures. The actual structure is an average of all of the resonance structures.

21. Infrared- Bond Absorbances
Figure: UN
Caption:
The IR spectrum has distinct regions. The left of the spectrum shows the C-H, O-H, and N-H stretches. The triple bonds absorb around 2200 cm-1 followed by the double bonds to the right at around 1700 cm-1. The region below 1400 cm-1 is called the fingerprint region.

22. Infrared- Bond Absorbances
Figure: UN
Caption:
The IR spectrum has distinct regions. The left of the spectrum shows the C-H, O-H, and N-H stretches. The triple bonds absorb around 2200 cm-1 followed by the double bonds to the right at around 1700 cm-1. The region below 1400 cm-1 is called the fingerprint region.

23. Infrared- Bond Absorbances
Figure: UN
Caption:
The IR spectrum has distinct regions. The left of the spectrum shows the C-H, O-H, and N-H stretches. The triple bonds absorb around 2200 cm-1 followed by the double bonds to the right at around 1700 cm-1. The region below 1400 cm-1 is called the fingerprint region.

24. Computational Chemistry
Polarity: Molview ( Jmol
Figure: 08-07
Color coded electron density distribution: red-highest, blue lowest, green balanced
The more distinct the red –blue colors means the more polar the molecule.

25. Polarity & Physical Properties Ozone and Waternm
The Lotus flower
Water & dirt repellancy: solubility?
Resultant Molecular Dipoles > 0
Solubility: Polar molecules that dissolve or are dissolved in like molecules
New Water-Repellent Material Mimics Lotus Leaves John Roach
for National Geographic News
February 27, 2003
Dirt-repelling paint, based on the qualities of the lotus leaf, being
developed at Bonn University.

26. Legos of Chemical Biology
Amino Acids
Legos of Chemical Biology
Amino acids contain carbon, hydrogen, oxygen, and nitrogen, which resemble the following shapes & structural components
20 different amino acids are encoded by the genetic code, which is archived in DNA.
Hundreds of amino acids link together with amide (peptide) bonds to form proteins, which are the machinery for the chemistry of life.
There are less than 20,000 total proteins produced from humans’ entire genome, each coded by a specific gene in DNA’s ~3 billion genetic bases.

27. Indispensible Biopolymers
Amino Acids Proteins
Indispensible Biopolymers
Acetylcholinesterase (ACE)
ACE, an enzyme, which catalyzes a key reaction in a repetitive biochemical cycle that is crucial to neurological and physiological functions in humans…. and insects among others.
4,496 atoms; 4,404 bonds
574 amino acid residues

28. Biological Reactions eg. Fermentation
A 3900-year-old clay tablet, which was found in Iraq between the Tigris and Euphrates rivers, had a Sumerian poem ( honoring Ninkasi, the patron goddess of brewing. It contains the oldest surviving beer recipe, describing the fermentation of the carbohydrates found in bread, bappir, made from barley, honey, dates and sweet aromatic herbs. The global availability of carbohydrates and native microbes (yeasts) has led to the production of many different types of beers, ales, wines, and fruit based alcoholic beverages in many countries throughout the world. [The bottle on the left was found in Eugene, Oregon, ……. But, it dates only to 2016.]