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Organic Chemistry I Fall 2013. Let’s try to avoid this scenario. 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.
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Organic Chemistry I Fall 2013 Let’s try to avoid this scenario...
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.
Organic Chemistry I Fall 2013 Chemistry is the study of matter, including its composition, properties, and transformations. Organic chemistry is the study of compounds containing carbon and hydrogen.
Most Common Elements in Organic Compounds are C, H, N, O, F, P, S, Cl, Br, I
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)?
Periodic Table of the Elements Carbon is in group 4A. How many valence e- does carbon have? How many bonds does carbon form?
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.
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
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.
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
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
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
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 • One s-orbital and one sp3-orbital
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 C=N bond stronger? • In the molecule DMAP, is the C-N bond or the C=N bond stronger?