Chapter 2

Question 1

Alkanes are _______ hydrocarbons.

Answer 1

saturated

Question 2

Alkenes are _______ hydrocarbons.

Answer 2

unsaturated

Question 3

Alkynes are _______ hydrocarbons.

Answer 3

unsaturated

Question 4

Arenes are _______ hydrocarbons.

Answer 4

unsaturated

Question 5

Saturated hydrocarbons:

Answer 5

Contain only carbon-carbon single bonds

Question 6

Unsaturated hydrocarbons

Answer 6

Contain one or more carbon-carbon double bond, triple bond, or benzene ring.

Question 7

Alkane general molecular formula

Answer 7

C(n)H(2n+2)

Question 8

Constitutional isomers

Answer 8

Have the same molecular formula but different atom connectivity.

Question 9

Different constitutional isomers have:

Answer 9

different physical properties

Question 10

Alkyl group

Answer 10

A substituent group derived from an alkane by the removal of a hydrogen atom

Question 11

-e

Answer 11

hydrocarbon

Question 12

-ol

Answer 12

alcohol

Question 13

-al

Answer 13

aldehyde

Question 14

-amine

Answer 14

amine

Question 15

-one

Answer 15

ketone

Question 16

-oic acid

Answer 16

carboxylic acid

Question 17

Cycloalkane

Answer 17

A saturated hydrocarbon that contains atoms bonded to form a ring

Question 18

Cyclic hydrocarbon

Answer 18

A hydrocarbon that contains carbon atoms joined to form a ring

Question 19

Cycloalkane molecular formula:

Answer 19

C(n)H(2n)

Question 20

If there are two substituents on a cycloalkane:

Answer 20

number the ring beginning with the substituent of lower alphabetic order.

Question 21

If there are three or more substituents:

Answer 21

number the ring to give substituted carbons the lowest numbers (sum)

Question 22

sec-

Answer 22

Indicates that a functional group is bonded to a secondary carbon atom in a chain of four or more carbon atoms

Question 23

tert-

Answer 23

Indicates that a functional group is attached to a tertiary carbon atom.

Question 24

iso-

Answer 24

Used to indicate that all carbons in a molecule are in a continuous chain, except one carbon that is part of an isopropyl group at the end of the chain.

Question 25

Bicycloalkane

Answer 25

An alkane that consists of two rings that share two carbon atoms

Question 26

Bridgehead carbons

Answer 26

The shared carbons in a bicycloalkane

Question 27

Bicycloalkane formula

Answer 27

C(n)H(2n-2)

Question 28

Staggered conformation

Answer 28

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 atom.

Question 29

Eclipsed conformation

Answer 29

A conformation about a carbon-carbon single bond in which the atoms or groups on one carbon are as close as possible to the atoms or groups on an adjacent carbon.

Question 30

Torsional strain

Answer 30

Strain that arises when nonbonded atoms separated by three bonds are forced from a staggered conformation to an eclipsed conformation. Torsional strain is also called eclipsed-interaction strain.

Question 31

Eclipsed conformations have ______ energy.

Answer 31

higher

Question 32

Anti conformation

Answer 32

A conformation about a single bond in which two groups on adjacent carbons lie at a dihedral angle of 180.

Question 33

Gauche conformation

Answer 33

A conformation about a single bond of an alkane in which two groups on adjacent carbons lie at a dihedral angle of 60.

Question 34

Gauche and anti conformations are ______ conformations.

Answer 34

staggered

Question 35

Steric strain

Answer 35

The strain that arises when nonbonded atoms separated by four or more bonds are forced closer to each other than their atomic (contact) radii would allow. Steric strain is also called nonbonded interaction strain, or van der Waals strain.

Question 36

Small ring strain

Answer 36

A strain associated with ring sizes below six that arises from nonoptimal bond angles.

Question 37

The observed C-C-C bond angles in cyclopropane:

Answer 37

60

Question 38

How does puckering a ring alter the strain energy?

Answer 38

1) It decreases the torsional strain associated with eclipsed interactions 2) increases further the angle strain caused by the compression of C-C-C bond angles

Question 39

Chair conformation

Answer 39

The most stable nonplanar conformation of a cyclohexane; all bond angles are 110.9, close to the optimum. All bonds on adjacent carbons are staggered.

Question 40

Axial bonds

Answer 40

Perpendicular bonds

Question 41

Equatorial bonds

Answer 41

Lies roughly along the equator of the ring

Question 42

Diaxial interaction

Answer 42

The steric strain arising from interaction between an axial substituent and an axial hydrogen on the same side of the chair conformation.

Question 43

Which is more stable, axial or equatorial substituents?

Answer 43

Equatorial

Question 44

Stereoisomers

Answer 44

Compounds that have the same molecular formula and the same connectivity, but different orientation in space.

Question 45

Stereocenter

Answer 45

An atom (most commonly a carbon atom) about which exchange of two groups produces a different stereoisomer.

Question 46

Cis, trans isomers

Answer 46

Have the same molecular formula and same connectivity of atoms, but the arrangement of their atoms in space cannot be interconverted by rotation about single bonds.

Question 47

Cis

Answer 47

substituents are on the same side of the ring

Question 48

Trans

Answer 48

substituents are on opposite sides of the ring

Question 49

Which is more stable, cis or trans isomers?

Answer 49

Trans

Question 50

What intermolecular force do cycloalkanes contain?

Answer 50

dispersion forces

Question 52

The strength of dispersion forces tend to increase with:

Answer 52

increasing molecular mass and size

Question 53

Boiling points of alkanes are:

Answer 53

low

Question 54

As the number of atoms and molecular weight of alkanes increase, the boiling point ______.

Answer 54

increases

Question 55

Alkanes containing 1 to 4 carbons are _____ at room temperature.

Answer 55

gases

Question 56

Alkanes containing 5 to 17 carbons are ________ at room temperature.

Answer 56

colorless liquids

Question 57

Alkanes containing 18 or more carbons are ______ at room temperature.

Answer 57

white, waxy solids

Question 58

Constitutional isomers are ______ compounds.

Answer 58

different

Question 59

As the branching of an alkane increases, boiling point ______.

Answer 59

increases

Question 60

Oxidation of alkanes

Answer 60

Oxidation of alkanes to carbon dioxide and water is the basis for their use as energy sources of heat and power.

Question 61

In hydrocarbon oxidations, the energy of the products is ______ than that of the reactants.

Answer 61

less

Question 62

Heat of combustion

Answer 62

The energy of the products minus that of the reactants

Question 63

Longer straight-chained alkanes have a _____ melting point than shorter straight-chained alkanes.

Answer 63

higher

Question 64

The density of an alkane _____ with increasing molecular weight.

Answer 64

increases

Question 65

Branched alkanes are _____ stable than straight-chained alkanes.

Answer 65

more

Question 66

Branched alkanes have a ____ boiling point than straight-chained alkanes.

Answer 66

lower