Alkanes Flashcards
1
Q
Molecular formula of methane
A
2
Q
Molecular formula of ethane
A
3
Q
Molecular formula of propane
A
4
Q
Molecular formula of butane
A
5
Q
Molecular formula of pentane
A
6
Q
Molecular formula of hexane
A
7
Q
Molecular formula of heptane
A
8
Q
Molecular formula of octane
A
9
Q
Molecular formula of nonane
A
10
Q
Molecular formula of decane
A
11
Q
Molecular formula of tridecane
A
12
Q
Molecular formula of undecane
A
13
Q
Molecular formula of dodecane
A
14
Q
Molecular formula of tetradecane
A
15
Q
Molecular formula of pentadecane
A
16
Q
Molecular formula of hexadecane
A
17
Q
Molecular formula of heptadecane
A
18
Q
Molecular formula of octadecane
A
19
Q
Molecular formula of nonadecane
A
20
Q
Molecular formula of eicosane
A
21
Q
Condensed structural formula of propane
A
22
Q
Condensed structural formula of butane
A
23
Q
Condensed structural formula of octane
A
24
Q
Condensed structural formula of tetradecane
A
25
Condensed structural formula of nonadecane
26
Undec-
11
27
Dodec-
12
28
Tridec-
13
29
Tetradec-
14
30
Pentadec-
15
31
Hexadec-
16
32
Heptadec-
17
33
Octadec-
18
34
Nonadec-
19
35
Eicos-
20
36
Are Alkanes saturated or unsaturated hydrocarbons?
Saturated.
They contain only carbon-carbon single bonds and each carbon has the maximum number of hydrogens bonded to it.
37
Are Alkenes saturated or unsaturated hydrocarbons?
Unsaturaed. Contains one or more carbon-carbon double bonds, triple bonds, or benzene rings.
38
Are Alkynes saturated or unsaturated hydrocarbons?
Unsaturaed. Contains one or more carbon-carbon double bonds, triple bonds, or benzene rings.
39
Are Arenes saturated or unsaturated hydrocarbons?
Unsaturaed. Contains one or more carbon-carbon double bonds, triple bonds, or benzene rings.
40
What is the general molecular formula for an alkane?
41
What is a constitutional isomer?
Compounds that have the same molecular formula but different structural formulas
42
Name this molecule
2-methylpropane
| (an isomer of butane)
43
True or False?
All compounds that have the same molecular formula but different structural formulas (different connectivities of their atoms) are constitutional isomers.
True
44
Same compound or constitutional isomers?
Constitutional isomers
45
Same compound or constitutional isomers?
Same compound
46
Name compound
4-methyloctane
47
What is an Alkyl group?
A substituent group derived from an alkane by the removal of a hydrogen atom
48
Name compound
2-methylpentane
49
Name compound
2,4-Dimethylhexane
50
Name compound
3-Ethyl-5-methylheptane
51
Name compound
4-Ethyl-2,2-dimethylhexane
52
Which numbering is correct and what is the name of the compound?
3-Ethyl-2-methylhexane
53
Name the alkyl group
Methyl
54
Name the alkyl group
Ethyl
55
Name the alkyl group
Propyl
56
Name the alkyl group
1-Methylethyl
| (isopropyl, iPr)
57
Name the alkyl group
Butyl (Bu)
58
Name the alkyl group
2-Methylpropyl
| (isobutyl, iBu)
59
Name the alkyl group
1-Methylpropyl
| (sec-butyl, s-Bu)
60
Name the alkyl group
1,1-Dimethylethyl
| (tert-butyl, t-Bu)
61
Name the alkyl group
Pentyl
62
Name the alkyl group
3-Methylbutyl
| (isopentyl)
63
Name the alkyl group
2-Methylbutyl
64
Name the alkyl group
2,2-Dimethylpropyl
| (neopentyl)
65
What is the IUPAC and common name of this alkane?
2-Methyl-4(1-methylethyl)heptane
4-isopropyl-2-methylheptane
66
Name this alkane
2-Methylbutane
67
Name this alkane
2-Methyl-5-(1-methylethyl)octane
68
Name this alkane
4-(1-Methylethyl)-4-propyloctane
69
What is the common name?
Butane
70
Provide common name
Isobutane
71
Give common name
Pentane
72
Give the common name
Isopentane
73
Give common name
Neopentane
74
What does this suffix mean?
Hydrocarbon
75
What does this suffix mean?
Alcohol
76
What does this suffix mean?
Aldehyde
77
What does this suffix mean?
Keytone
78
What does this suffix mean?
Carboxylic acid
79
What does this infix mean?
All single bonds
80
What does this infix mean?
One or more double bonds
81
What does this infix mean?
One or more triple bonds
82
Give IUPAC name
Propanone
83
Give IUPAC name
Pentanal
84
Give IUPAC name
Cyclopentanol
85
Give IUPAC name
Cycloheptene
86
Define **Cycloalkane**
A saturated hydrocarbon that contains carbons joined to form a ring.
87
Name
Cyclopropane
88
Name
Cyclobutane
89
Name
Cyclopentane
90
Name
Cyclohexane
91
What is the general formula for a cycloalkane?
92
What is the difference between these two alkanes?
C6H12 and C6H14
This is a cyclohexane
93
Name
1-Ethyl-4-(1,1-dimethylethyl)cyclohexane
or
1-tert-butyl-4-ethylcyclohexane
94
Name
2-Ethyl-1,4-dimethylcyclohexane
95
Name
96
Name
97
Name
98
Define **bicycloalkane**
An alkane that contains two rings that share two carbon atoms
99
What is the general formula of a bicycloalkane?
100
Name
101
Name
102
Define **conformation**
Any three-dimensional arrangement of atoms in a molecule that results from rotation about a single bond.
103
# Define: **Staggered** **conformation**
A conformation about a carbon- carbon single bond in which the atoms or groups on one carbon are as far apart as possible from atoms or groups on an adjacent carbon.
104
Define: **Newman Projection**
A way to view a molecule by looking along a carbon-carbon single bond to help evaluate the relative orientations of attached groups.
105
Staggered or Eclipsed?
Staggered
106
Staggered or eclipsed?
Eclipsed
107
Define: **Eclipsed conformation**
108
Define: **Dihedral angle**
The angle created by 2 intersecting planes
109
Dihedral angle of eclipsed conformation?
110
Dihedral angle of a staggered conformation?
111
The difference in energy between an eclipsed conformation and a staggered conformation of ethane is approximately?
**12.6 kJ (3.0 kcal)/mol**
(approximately 4.2 kJ (1.0 kcal)/mol for each eclipsed H/H) and is referred to as **torsional strain.**
112
What kind of energy change is this?
Torsional strain
113
What can be observed from this diagram?
The eclipsed conformations are approximately
12.6 kJ (3.0 kcal)/mol higher in energy than the staggered conformations.
114
115
116
117
118
Gauche or anti?
Gauche
119
Define: **torsional strain**
Torsional strain (also called eclipsed-interaction strain) arises when nonbonded atoms separated by three bonds are forced from a staggered conformation to an eclipsed conformation.
120
Name
1,2-dichloroethane
121
Define: **single ring strain**
exists in ring sizes below six A strain associated with ring carbons and is due to the C-C-C-C bond angles not being able to achieve the optimal sizes below six that arises from the tetrahedral angle of 109.5°
122
true or false:
Because the decrease in torsional strain is greater than the increase in angle strain, puckered cyclobutane is more stable than planar cyclobutane.
Because the decrease in torsional strain is greater than the increase in angle strain, puckered cyclobutane is more stable than planar cyclobutane.
123
Define: **chair conformation**
124
Define
125
Define
126
Why is there little strain in the chair conformation of cyclohexane?
In this conformation, all C-C-C bond angles are 110.9° (minimizing angle strain) and all hydrogens on adjacent carbons are staggered with respect to one another (minimizing torsional strain). In addition, no two atoms are close enough to each other for nonbonded interaction strain to exist. Thus, there is little strain in a chair conformation of cyclohexane.
127
128
Boat or chair conformation?
Chair
129
Boat or chair conformation?
Boat
130
Define
131
Define
132
Define
133
Name
134
Name
135
Why are *cis* isomers less stable (more energy) than *trans* isomers?
The cis isomer is approximately 7.1 kJ (1.7 kcal)/mol higher in energy (less stable) than the trans isomer because of the steric strain of the methyl groups on adjacent carbons in the cis isomer.
136
Define: **stereocenter**
137
Name
138
Name
139
Name
140
Name
141
Are alkanes polar or non-polar compounds?
Non polar compounds. C-H bonds only have a difference of 0.4 electronegativity
142
The most important property of alkanes and cycloalkanes?
The most important property of alkanes and cycloalkanes is their almost complete lack of polarity
143
What is the weakest intermolecular force?
Dispersion forces
144
Alkanes containing 1 to 4 carbons are ____ at room temperature?
Gases
145
146
What is the most economically important reaction of alkanes?
The oxidation of alkanes by O2 to give carbon dioxide and water
147
Define: **heat of combustion**
The heat of combustion is the energy of products minus the energy of the reactants
148
As branching increases, does heat of combustion increase or decrease?
does stability increase or decrease?
As branching increases, heat of combustion **decreases** and stability **increases**
149
What are the three major sources of alkanes throughout the world?
The fossil fuels: natural gas, petroleum, and coal
150
Define **Cracking**
Cracking is a process whereby a saturated hydrocarbon is converted into an unsaturated hydrocarbon plus H2.
151
\_\_\_\_\_ is a thick, viscous liquid mixture of thousands of compounds, most of them hydrocarbons, formed from the decomposition of marine plants and animals.
**Petroleum**
152
What is this process?
**Catalytic reforming**
153
