Alkanes Flashcards
Molecular formula of methane
Molecular formula of ethane
Molecular formula of propane
Molecular formula of butane
Molecular formula of pentane
Molecular formula of hexane
Molecular formula of heptane
Molecular formula of octane
Molecular formula of nonane
Molecular formula of decane
Molecular formula of tridecane
Molecular formula of undecane
Molecular formula of dodecane
Molecular formula of tetradecane
Molecular formula of pentadecane
Molecular formula of hexadecane
Molecular formula of heptadecane
Molecular formula of octadecane
Molecular formula of nonadecane
Molecular formula of eicosane
Condensed structural formula of propane
Condensed structural formula of butane
Condensed structural formula of octane
Condensed structural formula of tetradecane
Condensed structural formula of nonadecane
Undec-
11
Dodec-
12
Tridec-
13
Tetradec-
14
Pentadec-
15
Hexadec-
16
Heptadec-
17
Octadec-
18
Nonadec-
19
Eicos-
20
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.
Are Alkenes saturated or unsaturated hydrocarbons?
Unsaturaed. Contains one or more carbon-carbon double bonds, triple bonds, or benzene rings.
Are Alkynes saturated or unsaturated hydrocarbons?
Unsaturaed. Contains one or more carbon-carbon double bonds, triple bonds, or benzene rings.
Are Arenes saturated or unsaturated hydrocarbons?
Unsaturaed. Contains one or more carbon-carbon double bonds, triple bonds, or benzene rings.
What is the general molecular formula for an alkane?
What is a constitutional isomer?
Compounds that have the same molecular formula but different structural formulas
Name this molecule
2-methylpropane
(an isomer of butane)
True or False?
All compounds that have the same molecular formula but different structural formulas (different connectivities of their atoms) are constitutional isomers.
True
Same compound or constitutional isomers?
Constitutional isomers
Same compound or constitutional isomers?
Same compound
Name compound
4-methyloctane
What is an Alkyl group?
A substituent group derived from an alkane by the removal of a hydrogen atom
Name compound
2-methylpentane
Name compound
2,4-Dimethylhexane
Name compound
3-Ethyl-5-methylheptane
Name compound
4-Ethyl-2,2-dimethylhexane
Which numbering is correct and what is the name of the compound?
3-Ethyl-2-methylhexane
Name the alkyl group
Methyl
Name the alkyl group
Ethyl
Name the alkyl group
Propyl
Name the alkyl group
1-Methylethyl
(isopropyl, iPr)
Name the alkyl group
Butyl (Bu)
Name the alkyl group
2-Methylpropyl
(isobutyl, iBu)
Name the alkyl group
1-Methylpropyl
(sec-butyl, s-Bu)
Name the alkyl group
1,1-Dimethylethyl
(tert-butyl, t-Bu)
Name the alkyl group
Pentyl
Name the alkyl group
3-Methylbutyl
(isopentyl)
Name the alkyl group
2-Methylbutyl
Name the alkyl group
2,2-Dimethylpropyl
(neopentyl)
What is the IUPAC and common name of this alkane?
2-Methyl-4(1-methylethyl)heptane
4-isopropyl-2-methylheptane
Name this alkane
2-Methylbutane
Name this alkane
2-Methyl-5-(1-methylethyl)octane
Name this alkane
4-(1-Methylethyl)-4-propyloctane
What is the common name?
Butane
Provide common name
Isobutane
Give common name
Pentane
Give the common name
Isopentane
Give common name
Neopentane
What does this suffix mean?
Hydrocarbon
What does this suffix mean?
Alcohol
What does this suffix mean?
Aldehyde
What does this suffix mean?
Keytone
What does this suffix mean?
Carboxylic acid
What does this infix mean?
All single bonds
What does this infix mean?
One or more double bonds
What does this infix mean?
One or more triple bonds
Give IUPAC name
Propanone
Give IUPAC name
Pentanal
Give IUPAC name
Cyclopentanol
Give IUPAC name
Cycloheptene
Define Cycloalkane
A saturated hydrocarbon that contains carbons joined to form a ring.
Name
Cyclopropane
Name
Cyclobutane
Name
Cyclopentane
Name
Cyclohexane
What is the general formula for a cycloalkane?
What is the difference between these two alkanes?
C6H12 and C6H14
This is a cyclohexane
Name
1-Ethyl-4-(1,1-dimethylethyl)cyclohexane
or
1-tert-butyl-4-ethylcyclohexane
Name
2-Ethyl-1,4-dimethylcyclohexane
Name
Name
Name
Define bicycloalkane
An alkane that contains two rings that share two carbon atoms
What is the general formula of a bicycloalkane?
Name
Name
Define conformation
Any three-dimensional arrangement of atoms in a molecule that results from rotation about a single bond.
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.
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.
Staggered or Eclipsed?
Staggered
Staggered or eclipsed?
Eclipsed
Define: Eclipsed conformation
Define: Dihedral angle
The angle created by 2 intersecting planes
Dihedral angle of eclipsed conformation?
Dihedral angle of a staggered conformation?
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.
What kind of energy change is this?
Torsional strain
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.
Gauche or anti?
Gauche
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.
Name
1,2-dichloroethane
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°
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.
Define: chair conformation
Define
Define
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.
Boat or chair conformation?
Chair
Boat or chair conformation?
Boat
Define
Define
Define
Name
Name
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.
Define: stereocenter
Name
Name
Name
Name
Are alkanes polar or non-polar compounds?
Non polar compounds. C-H bonds only have a difference of 0.4 electronegativity
The most important property of alkanes and cycloalkanes?
The most important property of alkanes and cycloalkanes is their almost complete lack of polarity
What is the weakest intermolecular force?
Dispersion forces
Alkanes containing 1 to 4 carbons are ____ at room temperature?
Gases
What is the most economically important reaction of alkanes?
The oxidation of alkanes by O2 to give carbon dioxide and water
Define: heat of combustion
The heat of combustion is the energy of products minus the energy of the reactants
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
What are the three major sources of alkanes throughout the world?
The fossil fuels: natural gas, petroleum, and coal
Define Cracking
Cracking is a process whereby a saturated hydrocarbon is converted into an unsaturated hydrocarbon plus H2.
_____ is a thick, viscous liquid mixture of thousands of compounds, most of them hydrocarbons, formed from the decomposition of marine plants and animals.
Petroleum
What is this process?
Catalytic reforming
