Organic Chemistry Exam 1 Flashcards
What is the electronegativity?
- Nitrogen
Electronegativity=3.0
If the region of electron density around an atom is 4, what is the predicted distribution and bond angles?
Tetrahedral, 109.5 degrees
of carbon atoms:
8
Oct-
of carbon atoms:
11
Undec-
How many valence electrons, preferred bond #, and bond range?
- Nitrogen
Valence Electrons: 5
Preferred # of Bonds: 3
Bond Range: 1-4
of carbon atoms:
6
Hex-
Preferred # of bonds formula
8
-group # of nonmetal
___________________
=preferred # of bonds
of carbon atoms:
10
Dec-
What is the electronegativity?
- Oxygen
Electronegativity= 3.4
What is the electronegativity?
- Flourine
Electronegativity=4.0
What is the electronegativity?
- Iodine
Electronegativity= 2.7
of carbon atoms:
2
Eth-
of carbon atoms:
5
Pent-
What is the electronegativity?
- Phosphorus
Electronegativity=2.2
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
Describe how to analyze bond length
- Atomic size: larger atoms have longer bonds
- Triple bond is shorter than a double bond, which is shorter than a single bond
- Fraction of s character in the bond:
more s character: shorter bond
less s character: longer bond
of carbon atoms:
4
But-
If the region of electron density around an atom is 2, what is the predicted distribution and bond angles?
Linear, 180 degrees
How many valence electrons, preferred bond #, and bond range?
- Sulfur
Valence Electrons: 6
Preferred # of Bonds: 2
Bond Range: 1-3
What is the electronegativity?
- Chlorine
Electronegativity=3.2
What is the order of the halogens?
F Cl Br I
F-FUCK
Cl-CLOWNS
Br-BRING
I-ICE
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:
- Un-paired lone electron pairs
- Pi bonds
of carbon atoms:
12
Dodec-
of carbon atoms:
9
Non-
of carbon atoms:
1
Meth-
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
of carbon atoms:
7
Hept-
Define the criteria for evaluating if a structure is a legitimate contributing resonance structure
- 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.
- Contributing structures with incomplete octets on very electronegative elements such as N, O, F, and Cl are rarely considered.
- Contributing structures with formal charges greater than +1 or -1 are rarely considered.
- Contributing structures in which there is an expanded octet on H, C, N, O, or F are never considered.
What is the electronegativity?
- Bromine
Electronegativity=3.0
What is the electronegativity?
- Carbon
Electronegativity=2.6
How many valence electrons, preferred bond #, and bond range?
- Hydrogen
Valence Electrons: 1
Preferred # of Bonds: 1
Bond Range: 1
What is the electronegativity?
- Hydrogen
Electronegativity=2.2
of carbon atoms:
3
Prop-
What is the electronegativity?
- Sulfur
Electronegativity=2.6
How many valence electrons, preferred bond #, and bond range?
- Oxygen
Valence Electrons: 6
Preferred # of Bonds: 2
Bond Range: 1-3
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
How many valence electrons, preferred bond #, and bond range?
- Phosphorus
Valence Electrons: 5
Preferred # of Bonds: 3
Bond Range: 1-4
Describe the VSEPR analysis for non-ideal bond angles
- lone pairs are larger than bonded pairs (i.e. lessens the bond angles between other subsituents)
- multiple bonds are bigger than single bonds (i.e. lessens the bond angles between other substituents)
- Electron pair in an electronegative atom may be further away, increasing bond angles of the other substituents
How many valence electrons, preferred bond #, and bond range?
- Carbon
Valence Electrons: 4
Preferred # of Bonds: 4
Bond Range: 3-4
If the region of electron density around an atom is 3, what is the predicted distribution and bond angles?
trigonal planar, 120 degrees
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
Formal charge formula
valence electrons
-#unpaired electrons
-(1/2) # bonded electrons
______________________
=Formal Charge
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
