Organic Chemistry Exam 1 Flashcards Preview

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Flashcards in Organic Chemistry Exam 1 Deck (43):
1


What is the electronegativity?

  • Nitrogen

Electronegativity=3.0

2

If the region of electron density around an atom is 4, what is the predicted distribution and bond angles?

Tetrahedral, 109.5 degrees

3


# of carbon atoms:
8

Oct-

3

# of carbon atoms:
11

Undec-

5


How many valence electrons, preferred bond #, and bond range?

  • Nitrogen

Valence Electrons: 5

Preferred # of Bonds: 3

Bond Range: 1-4

7

# of carbon atoms:
6

Hex-

8


Preferred # of bonds formula

8
-group # of nonmetal
___________________
=preferred # of bonds

9


# of carbon atoms:
10

Dec-

10


What is the electronegativity?

  • Oxygen

Electronegativity= 3.4

11


What is the electronegativity?

  • Flourine

Electronegativity=4.0

11


What is the electronegativity?

  • Iodine

Electronegativity= 2.7

12


# of carbon atoms:
2

Eth-

12


# of carbon atoms:
5

Pent-

14

What is the electronegativity?

  • Phosphorus

Electronegativity=2.2

14


Describe the hybridization bodel for non-ideal bond angles

More s character than ideal: smaller than ideal bond angles

Less s character than ideal: larger than ideal bond angles

15

Describe how to analyze bond length

  1. Atomic size: larger atoms have longer bonds
  2. Triple bond is shorter than a double bond, which is shorter than a single bond
  3. Fraction of s character in the bond:

more s character: shorter bond

less s character: longer bond

16


# of carbon atoms:
4

But-

16



If the region of electron density around an atom is 2, what is the predicted distribution and bond angles?

Linear, 180 degrees

17

How many valence electrons, preferred bond #, and bond range?

  • Sulfur

Valence Electrons: 6

Preferred # of Bonds: 2

Bond Range: 1-3

18


What is the electronegativity?

  • Chlorine

Electronegativity=3.2

18


What is the order of the halogens?

F   Cl   Br   I

 

F-FUCK
Cl-CLOWNS
Br-BRING
I-ICE

19


Define Resonance


A theory that many molecules are best described as a hybrid of several Lewis structures. To draw these structures, only the following may be moved:

  1. Un-paired lone electron pairs
  2. Pi bonds

20


# of carbon atoms:
12

Dodec-

21


# of carbon atoms:
9

Non-

23


# of carbon atoms:
1

Meth-

24


What is the third row of the periodic table?

(13-17)
Al   Si   P   S   Cl 

Al-ALL
Si-SIZABLE
P-PENIS
S-STICKS
Cl-CLIMAX

25


# of carbon atoms:
7

Hept-

26

Define the criteria for evaluating if a structure is a legitimate contributing resonance structure

  1. Contributing structures with two formal charges in which the more electronegative element bears the positive charge and the less electronegative element bears the negative charge are rarely considered.
  2. Contributing structures with incomplete octets on very electronegative elements such as N, O, F, and Cl are rarely considered.
  3. Contributing structures with formal charges greater than +1 or -1 are rarely considered.
  4. Contributing structures in which there is an expanded octet on H, C, N, O, or F are never considered.

28


What is the electronegativity?

  • Bromine

Electronegativity=3.0

30

What is the electronegativity?

  • Carbon

Electronegativity=2.6

31


How many valence electrons, preferred bond #, and bond range?

  • Hydrogen

Valence Electrons: 1

Preferred # of Bonds: 1

Bond Range: 1

32


What is the electronegativity?

  • Hydrogen

Electronegativity=2.2

33


# of carbon atoms:
3

Prop-

34

What is the electronegativity?

  • Sulfur

Electronegativity=2.6

35

How many valence electrons, preferred bond #, and bond range?

  • Oxygen

Valence Electrons: 6

Preferred # of Bonds: 2

Bond Range: 1-3

36


What is the second row of the periodic table?

(5-9)
B   C   N   O   F

B-BIG
C-CLOWNS
N-Near
O-OR
F-FAR

37

How many valence electrons, preferred bond #, and bond range?

  • Phosphorus

Valence Electrons: 5

Preferred # of Bonds: 3

Bond Range: 1-4

37


Describe the VSEPR analysis for non-ideal bond angles

  1. lone pairs are larger than bonded pairs (i.e. lessens the bond angles between other subsituents)
  2. multiple bonds are bigger than single bonds (i.e. lessens the bond angles between other substituents)
  3. Electron pair in an electronegative atom may be further away, increasing bond angles of the other substituents

38


How many valence electrons, preferred bond #, and bond range?

  • Carbon

Valence Electrons: 4

Preferred # of Bonds: 4

Bond Range: 3-4

40


If the region of electron density around an atom is 3, what is the predicted distribution and bond angles?

trigonal planar, 120 degrees

41

Of these, which are alphabetized in nomenclature?

  • di, tri, tetra, penta, hexa, etc..
  • Sec/tert
  • iso
  • neo
  • cyclo

Of these, which are alphabetized in nomenclature?

NOT ALPHABETIZED:

  • di, tri, tetra, penta, hexa, etc..
  • Sec/tert

 

ALPHABETIZED:

  • iso
  • neo
  • cyclo

42


Formal charge formula

# valence electrons
-#unpaired electrons
-(1/2) # bonded electrons
______________________
=Formal Charge

43


How many valence electrons, preferred bond #, and bond range?

  • Halogens (F, Cl, Br, I)

Valence Electrons: 7

Preferred # of Bonds: 1

Bond Range: 1-2* except for F, who can only have 1