Chapter 6

Question 1

An organic halide in which the halogen atom is bonded to an alkyl carbon

Answer 1

Alkyl halide

Question 2

An organic halide in which the halogen atom is bonded to an alkene carbon

Answer 2

Alkenyl halides

Question 3

An organic halide in which the halogen atom is attached to an aromatic ring, such as a benzene ring

Answer 3

Aryl halide

Question 4

An organic halide in which the halogen atom is bonded to a benzene ring; a specific type of aryl halide

Answer 4

Phenyl halide

Question 5

A reaction in which a nucleophile reacts with a substrate to replace a leaving group (a group that departs with an unshared electron pair)

Answer 5

Nucleophilic substitution reaction

Question 6

A Lewis base, an electron pair donor that seeks a positive center in a molecule

Answer 6

Nucleophile

Question 7

The substituent that departs from the substrate in a nucleophilic substitution reaction

Answer 7

Leaving group

Question 8

The molecule or ion that undergoes reaction

Answer 8

Substrate

Question 9

Cleavage by the solvent. A nucleophilic substitution reaction in which the nucleophile is a molecule of the solvent

Answer 9

Solvolysis

Question 10

A term that refers to rates of reactions

Answer 10

Kinetics

Question 11

A reaction whose rate-determining step involves two initially separate species

Answer 11

Bimolecular

Question 12

The number of species involved in a single step of a reaction (usually the rate-determining step)

Answer 12

Molecularity

Question 13

Literally, substitution nucleophilic bimolecular. A bimolecular nucleophilic substitution reaction that takes place in a single step. A nucleophile attacks a carbon bearing a leaving group from the back side, causing an inversion of configuration at this carbon and displacement of the leaving group

Answer 13

SN2

Question 14

A state on a potential energy diagram corresponding to an energy maximum (i.e., characterized by having higher potential energy than immediately adjacent states). The term transition state is also used to refer to the species that occurs at this state of maximum potential energy; another term used for this species is the activated complex

Answer 14

Transition state

Question 15

A reaction where bond forming and bond breaking occur simultaneously (in concert) through a single transition state

Answer 15

Concerted reaction

Question 16

A reaction that proceeds with a negative free-energy change

Answer 16

Exergonic reaction

Question 17

A reaction that proceeds with a positive free-energy change

Answer 17

Endergonic reaction

Question 18

A plot of free-energy changes that take place during a reaction versus the reaction coordinate. It displays free-energy changes as a function of changes in bond others and distances as reactants proceed through the transition state to become products

Answer 18

Free-energy diagram

Question 19

The abscissa in a potential energy diagram that represents the progress of the reaction. It represents the changes in bond orders and bond distances that must take place as reactants are converted to products

Answer 19

Reaction coordinate

Question 20

The difference in free energy between the transition state and the reactants

Answer 20

Free energy of activation

Question 21

Chemical studies that take into account the spatial aspects of molecules

Answer 21

Stereochemistry

Question 22

A reaction whose rate-determining step involves only one species

Answer 22

Unimolecular

Question 23

Literally, substitution nucleophilic unimolecular. A multi step nucleophilic substitution in which the leaving group departs in a unimolecular step before the attack of the nucleophile. The rate equation is first order in substrate but zero order in the attacking nucleophile

Answer 23

SN1 reaction

Question 24

If a reaction takes place in a series of steps, and if one step is intrinsically slower than all of the others, then the rate will be the same as (will be determined by) the rate of this slow step

Answer 24

Rate-determining step

Question 25

A transient species that exists between reactants and products in a state corresponding to a local energy minimum on a potential energy diagram

Answer 25

Intermediate

Question 26

Electron delocalization (via orbital overlap) from a filled bonding orbital to an adjacent unfilled orbital; generally has a stabilizing effect

Answer 26

Hyperconjugation

Question 27

A reaction that transforms an optically active compound into a racemic form is said to proceed with racemization; takes place whenever a reaction causes chiral molecules to be converted to an achiral intermediate

Answer 27

Racemization

Question 28

Literally, cleavage by the solvent. A nucleophilic substitution reaction in which the nucleophile is a molecule of the solvent

Answer 28

Solvolysis

Question 29

An effect on relative reaction rates caused when the spatial arrangement of atoms or groups at or near the reacting site hinders or retards a reaction

Answer 29

Steric hinderance

Question 30

A postulate stating that the structure and geometry of the transition state of a given step will show a greater resemblance to the reactants or products depending on which is closer to the transition state in energy. This means that the transition state of an endothermic step will resemble the products of that step more than the reactants, whereas the transition state of an exothermic step will resemble the reactants of that step more than the products

Answer 30

Hammond-Leffler postulate

Question 31

The relative reactivity of a nucleophile in an SN2 reaction as measured by relative rates of reaction

Answer 31

Nucleophilicity

Question 32

A polar solvent that doesn’t have a hydrogen atom attached to an electronegative element; doesn’t hydrogen bond with a Lewis base (e.g., a nucleophile)

Answer 32

Polar aprotic solvent

Question 33

A polar solvent that has at least one hydrogen atom bonded to an electronegative element. These hydrogen atoms of the solvent can form hydrogen bonds with a Lewis base (e.g., a nucleophile)

Answer 33

Polar protic solvent

Question 34

An effect on relative rates of reaction caused by the solvent. For example, the use of a polar solvent will increase the rate of reaction of an alkyl halide in an SN1 reaction

Answer 34

Solvent effect

Question 35

A measure of a solvent’s ability to insulate opposite charges from each other. The dielectric constant of a solvent roughly measures its polarity. Solvents with high dielectric constants are better solvents for ions than are solvents with low dielectric constants

Answer 35

Dielectric current

Question 36

The susceptibility of the electron cloud of an uncharged molecule to distortion by the influence of an electron charge

Answer 36

Polarizability

Question 37

A process that converts one functional group into another

Answer 37

Functional group interconversion