Units 4,5,6 Flashcards
(139 cards)
1
Q
Methane has how many carbons?
A
1 carbon
2
Q
Ethane has how many carbons?
A
2
3
Q
Propane
A
3
4
Q
Butane
A
4
5
Q
Pentane
A
5
6
Q
Hexane
A
6
7
Q
Heptane
A
7
8
Q
Octane
A
8
9
Q
Nonane
A
9
10
Q
Decane
A
10
11
Q
Alkanes
A
Saturated hydrocarbons with single bonds only.
12
Q
Alkenes
A
Unsaturated hydrocarbons with at least one carbon-carbon double bond.
13
Q
Alkynes
A
Unsaturated hydrocarbons with at least one carbon-carbon triple bond.
14
Q
Alcohols
A
Compounds with a hydroxyl group (-OH).
15
Q
Aldehydes
A
Compounds with a carbonyl group (-CHO) at the end of the chain.
16
Q
Ketones
A
Compounds with a carbonyl group (-C=O) within the carbon chain.
17
Q
Carboxylic Acids
A
Compounds with a carboxyl group (-COOH)
18
Q
Esters
A
Formed from a carboxylic acid and an alcohol.
19
Q
Ethers
A
Compounds with an oxygen atom linking two carbon chains.
20
Q
Amines
A
Compounds with an amino group (-NH2).
21
Q
Alcohol suffix
A
-ol
22
Q
Aldehydes suffix
A
-al
23
Q
Ketones suffix
A
-one
24
Q
Carboxylic acid suffix
A
-oic acid
25
-ane type of bond
Single bond
26
-ene type of bonds
Double bond
27
-yne type of bond
Triple bond
28
Methyl means
(-CH3)
29
Ethyl means
C2H5
30
Chloro
-Cl
31
Alkene functional group
Double bond, ends in -ene
32
Alkyne functional group
Triple bond, ends in -yne
33
Arene functional group
Six-membered ring with alternating double bonds and single bonds
34
Halide functional group
Group 17 atoms bonded to carbon, (F, Cl, Br, I)
35
Ether functional group
O between 2 Carbons, ends in -ether
36
Amine functional group
N bonded to C, ends in -amine
37
Alcohol functional group
OH bonded to C, ends in -ol
38
Imine functional group
N double bonded to C
39
Nitrile functional group
N triple bonded to C
40
Aldehydes functional group
O double bond C with an H bonded to C, ends in -al
41
Ketone
C=O, ends in -one
42
Carboxylic acid
C=O with an OH attached to C. Ends in -oic acid
43
Ester
C=O with an O bonded between 2 Carbons, ends in -oate
44
Amide
C=O with a N bonded to C
45
Acid chloride
C=O with Cl, -oyl chloride
46
Carboxylic acid and anhydride
2 C=O with a O between the C
47
Alkyl halide
C bonded to halogen (F,Cl,I,Br)
48
Phosphate
P with three O, one double bonded, 2 with negative. charge, and one shared with C
49
Thiol
SH bonded to C
50
Sulfide
S between 2 C
51
Disulfide
2 S between 2 C
52
Name all the Carbonyl groups (C=O) [draw them]
Aldehydes (C=O) - H
Ketones (C=O)
Carboxylic Acid (C=O) -OH
Esters (C=O) - O - C
Thioesters (C=O) - S - C
Amides (C=O) - N
Acid chlorides (C=O) - Cl
53
Saturation definition
Having only C-C and C-H bonds, therefore having the max amount of H per Carbon. (Alkanes)
54
What general formula does Alkanes have to calculate the number of carbons and Hydrogens?
Cn H2n+2
55
Definition of aliphatic
“Fat”, long carbon chains. Occasionally an alkane
56
What are straight chain alkanes, give examples
Compounds whose carbons are all connected in a row, (normal Alkanes)
Ex: butane, pentane
57
Conformations are
Different arrangements of atoms that result from bond rotation
58
Can double and triple bonds rotate?
No
59
Eclipsed energy and degrees
High energy, unstable, 0, 120, 240, 360
60
Staggered energy and degrees
Low energy, more stable, common! 60, 180, 300
61
Which is more stable, anti or gauche?
Anti because the largest groups are farthest away from each other, minimizing electron repulsion and being more stable
62
Anti conformation happens at
180 degrees, where the largest groups are farthest away
63
Gauche happens at
60 degrees, where the largest groups are close, but not eclipsed, inducing electron repulsion
64
If eclipsed it has
Torsional strain
65
If gauche
Steric interaction/strain
66
Energy costs for interactions in alkane conformers in kj/mol
H-H (eclipsed) = 4.0
H-CH3 (eclipsed) = 6.0
CH3-CH3 (eclipsed) = 11 (highest)
CH3-CH3 (gauche) 3.8 (lowest)
67
Is it possible to rotate a C-C bond in a ring?
No, the ring will break it rotation occurs
68
Define angle strain
The strain induced in a molecule when bond angles are forced to deviate from the ideal 109 degree tetrahedral value.
69
Does the twisted boa5 conformation have any angle strain?
No, it has steric strain and torsional strain
70
Which is higher in energy, the twisted boat or chair?
The twisted boat is higher in energy (23 kj/mol) therefore more unstable
71
1,3 diaxial interactions are
The energy difference between axial and equatorial from steric strain.
Example: An axial methyl group will be too close to axial hydrogens, resulting in steric strain
72
Additional reactions
When two reactants add together to form a single product with no leftovers.
73
Elimination reaction
When a single reaction splits into two products, often producing a small molecule as well such as HBr or water
74
Substitution reaction
Two reactions exchange parts to give two new products
75
Rearrangement reactions
when a single reactant reorganizes it’s bonds and produces an isomer product
76
Radical reactions are
Processes that involve symmetrical band-breaking and bond-making
77
What is a radical/free radical
A neutral chemical species that contains an odd number of elements electrons, has a single unpaired electron
78
Cis isomer
Methyl groups are on same face of the ring (both wedges or both dashes)
79
Trans isomer
When the methyl group is on opposite faces (one dashed, one wedge)
80
Which is more stable, trans isomer or cis?
Trans isomer, as its lowest energy is 0 kcal/mol while cis is 1.7 kcal/mol
81
How to draw trans isomer?
Both methyl groups should be either axial or equatorial
82
Free energy reaction equations
G = -RTlnKeq
Ken = e^(-G/RT)
83
R = gas constant =
1.987
84
Heterolytic
When one product has both lone e-
85
Homolytic
Both products get one line e-
86
Movement of 2 e- is represented by an
Arrow —>
87
Movement of 1 e- is represented by an
Fishhook —\
88
In unsymmetrical bond breaking it is
Polar and the products have a charge
89
In symmetrical bond breaking it is
Radical, where one e- stays with each product
90
Unsymmetrical bond making is when
Where one reactant gives both e- to form bond
91
Symmetrical bond making is when
Both reactants give 1 e- to make bond
92
Processes that are unsymmetrical are
Polar reactions
93
Processes that are symmetrical are
Radical reactions
94
If compound is asymmetrical it is
Going to be polar and go in the direction of the most EN atom
95
Nucleophile is
Negativity polarized, electron rich, donates e- to electron poor atom, and be neutral or negative
96
Electrophile
Positively polarized, electron poor, accepts e- from electron rich atom, and be neutral or positive
97
Neutral Compounds can often react as
nucleofiles or electrophiles
98
G < 0
Exergonic (favorable) releases energy
99
Reaction is favorable when
Keq > 1
G is negative
100
G > 0
Endergonic (unfavorable) needs energy to react
101
If product has stronger bonds the product is
More stable, the reaction is *exothermic*, **H < 0**
102
If products have weaker bonds
The products are less stable, endothermic, H > 0
103
Entropy is
Few reactants, more product, increase in disorder, favorable
104
S (Entropy) > 0, S (Entropy) < 0,
Favorable G, unfavorable G
105
H vs. S
Enthalpy (H) has more impact on G
106
1° is
When there is only one other carbon bonded to the carbon
107
2°
Two other carbons to the main carbon
108
3°
Three carbons to main carbon
109
Initiation is
The first step of radical chlorination, where the two Cl break apart and become radicals
110
Propagation is
When the radical forms a bond with an H. There is one reactant radical and one product radical
111
Termination is
When all radicals are gone
112
Which step is the determining step in radical halogenation
Propagation 1°
113
Is halogenation an equilibrium? (Reversible)
No, the Keq is much too large, very endothermic
114
Radical Carson’s are
Sp2 hybridized, planar, has unpainted e- in the p orbital
115
Radical carbons are
Sp2 hybridized, planar, has unpaired e- in p orbital
116
Is the 2° radical more stable than a 1° radical?
Yes, by 3 kcal/mol
117
How can you compare primary, secondary, and tertiary stability?
Through calculating the energies on bonds broken and bonds formed, then subtracting bonds broken from bonds formed. (BB - BF)
118
Order of radical stability
3° > 2° > 1° (tertiary is most stable)
119
What type of energy is needed to initiate a bromination reaction?
Heat AND light
120
How does the Hammond postulate determine that bromination is more selective than chlorination
Hammond’s postulate states that related species that are similar in energy have similar structure
So the transition state will be close to either reactants or products, whichever is closer in energy
Exothermic reaction: transition state resembles the reactants, transition state is early
Endothermic : transition state resembles products, is late
121
If a molecule is chiral
It isn’t superimposed on its mirror image
122
If achiral
It’s superimposed on its mirror image
123
Superimposed
When you rotate the mirror image to look exactly like the original
(Can’t) = Chiral
(Can) = achiral
124
Achiral molecules are
Identical due to being exact same when mirrored
125
Chiral molecules are
2 different isomers
126
how to determine radical stability?
calc BDE, the lower the BDE the less stable the radical
127
List from least stable to most stable: CH3, 1°, 2°, 3°
(Least stable) CH3, 1°, 2°, 3° (most stable)
The more substituted a radical is, the more stable
128
Why are 3° the most stable?
Radicals are e- deficient, wants to gain e- to satisfy octet
Any way to donate remaining e- to radical is stabilizing
Ways are through inductive effects and resonance
129
Alkyl groups are
Weakly inductive, and can donate e- through hyper conjugation
130
Hyperconjugation
Molecules with extra e- on another part will share their e- density with s- deficient areas, stabilizing the molecule
Nearby sigma orbitals can overlap with the partially filled p-orbital
131
Alkyl (Alkane missing a H)
Can
132
Structural isomers
Differ in the order in which atoms are bonded
133
Stereoisomers
Same bonding order but different arrangements of atoms in space
134
Types of stereoisomers
Enantiomers: non-superimposable mirror images
diastereomers: any stereoisomers that are **not** mirror images
135
Chiral center (marked with *)
Has four unique groups bonded to it
136
Chiral center rules
Most chiral molecules contain at least 1 chiral center
Not all chiral molecules have chiral centers
137
138
139
Strain energies
H-H eclipse 4
H-CH3 eclipse 6
Ch3-ch3 eclipse 11
Ch3-Ch3 gauche 3.8
