Organic Chemistry I

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Organic Chemistry I Fall 2013
Lets try to avoid this scenario...
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(No Transcript)
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Prevent Diene in this Class
Suggestions on how to succeed
Study frequently for shorter periods of time
instead of cramming before exams. Work on
problem sets in groups. Attend review sessions
and tutoring hours. Ask questions when the
material is unclear. Take advantage of office
hours seek help sooner rather than later. Dr.
A. makes mistakes please speak up if something
looks amiss. Please feel free to provide
feedback to help improve the course throughout
the semester.
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Organic Chemistry I Fall 2013
Chemistry is the study of matter, including its
composition, properties, and transformations. Or
ganic chemistry is the study of compounds
containing carbon and hydrogen.
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Most Common Elements in Organic Compounds are C,
H, N, O, F, P, S, Cl, Br, I
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Major Elements in the Human Body, by Mass
3 N, 2 Ca, 1 P
1 Cl, K, S, Na, Mg, and trace elements
10 H
65 O
18 C
Why such a large percentage of oxygen (O)?
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Periodic Table of the Elements

Carbon is in group 4A. How many valence e- does
carbon have? How many bonds does carbon form?
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Octet Rule
Atoms gain, lose, or share valence electrons to
end up with 8 valence electrons. Exceptions H,
He, Li, Be, B (first 5 elements) The noble
gases already have 8 valence electrons (except
He) so they do not form ions.
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Electron Dot Structures Show the Number of
Valence Electrons at Atom Has
Group 1A
Group 2A
Group 3A
Group 4A
Group 5A
Group 6A
Group 7A
Group 8A
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Elements Form Ions or Covalent Compounds to
Satisfy Octet Rule
Group 1A
Group 2A
Group 3A
Group 4A
Group 5A
Group 6A
Group 7A
Group 8A
Boron disobeys octet rule. P (phosphorus) can
form 3 or 5 bonds. S (sulfur) can form 2, 4 or 6
bonds.
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Electron Cloud Model of the Atom
Helium (He) 2 protons 2 neutrons
2 electrons

1 Ångström (Å) 10-10 m
1 femtometer (fm) 10-15 m 1 picometer (pm)
10-12 m 1 Ångström (Å) 10-10 m
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Electron Cloud Determines Atomic Size
If the atomic nucleus were the size of a
marble, a typical atom would be the size of a
football field
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Pop Quiz!

• 1) Atomic mass is primarily determined by
• Nucleus
• Electron cloud
• Both the nucleus and electron cloud
• 2) Atomic radius is primarily determined by
• Nucleus
• Electron cloud
• Both the nucleus and electron cloud
• How many covalent bonds do the following atoms
  form when neutral?
• C, O, Cl, N, H

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Pop Quiz! (continued)

• 4) Which of the following figures represents an
  sp3 orbital?
• 5) What is the approximate H-C-C bond angle in
  ethane (CH3CH3)?
• 90
• 110
• 120
• 180
• In the molecule methane (CH4), the C-H sigma
  bonds are formed between
• Two s-orbitals
• Two p-orbitals
• One s-orbital and one p-orbital
• One s-orbital and one sp2-orbital

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Pop Quiz! (continued)

• The structure of N,N-dimethylpyridine (DMAP) is
  shown below.
• a. How many carbon atoms are in DMAP?
• b. How many hydrogen atoms are in DMAP?
• Indicate the hybridization of each of the carbon
  and nitrogen atoms in DMAP.
• In the molecule DMAP, is the C-N bond or the CN
  bond stronger?
• In the molecule DMAP, is the C-N bond or the CN
  bond stronger?