Exam 3

Question 1

describe a chain reaction

Answer 1

fast and w/ many exothermic steps

Question 2

a radicle inhibitor does what?

Answer 2

creates a stable intermediate

Question 3

when an inhibitor reacts with a free radicle it the reaction is…

Answer 3

slow and endothermic

Question 4

a lewis acid has 2 other names what are they?

Answer 4

• electron pair acceptor

- electrophile

Question 5

a lewis base has 2 other names what are they?

Answer 5

• electron pair donor

- nucleophile

Question 6

a lewis acid has

Answer 6

an incomplete octet

Question 7

a lewis base has

Answer 7

an electron pair available for donating

Question 8

what are the 4 reactive intermediates?

Answer 8

1. carbocation
2. radicle
3. carbanion
4. carbene

Question 9

describe the carbocation stability

Answer 9

3>2>1> methyl

Question 10

describe inductive effect

Answer 10

donation of electron along sigma bonds

Question 11

describe hyperconjunction

Answer 11

overlap of sigma and p orbital

Question 12

order of stability for free radicles

Answer 12

3>2>1> methyl

Question 13

resonance structures can be used to stabilize both

Answer 13

• radicles

- carbocations

Question 14

describe carbanions

Answer 14

are nucleophilic and basic

Question 15

describe the stability of carbanions

Answer 15

CH3> 1>2>3

Question 16

a carbanion is a stronger _____ than an amine

Answer 16

base

Question 17

a carbene has both a lone pair and an empty p orbital therefore it can…

Answer 17

act as a nucleophile and an electrophile

Question 18

enantiomers have the same

Answer 18

• boiling/ melting point
• densities
• refractive index

Question 19

enantiomers rotate the plane of polarized light in the

Answer 19

same magnitude but in opposite directions

Question 20

formula for specific rotation

Answer 20

[a] = a(observed)/ C*L

Question 21

formula for optical purity

used when given degrees

Answer 21

o.p = (observed rotation)/ (rotation of pure enantiomer) *100%

Question 22

formula for e.e.

Answer 22

= (| d-l |)/(d+l) *100%

Question 23

formula for specific rotation formula when given percentages

Answer 23

(specific rotation of pure enantiomer) (o.p.)

Question 24

racemic mixtures have..

Answer 24

equal proportions of both d and l enantiomers

Question 25

in racemic mixtures there is no

Answer 25

optical activity

Question 26

the racemic mixture will have different b.p and m.p from the

Answer 26

2 enantiomers that were mixed

Question 27

allenes contain a

Answer 27

c=c=c unit

Question 28

what must happen in order for allenes to be chiral?

Answer 28

groups at the ends of carbons must be different

Question 29

in Fisher projections what is NOT allowed

Answer 29

90 degree turns

Question 30

diastereomers are

Answer 30

- molecules with 2 or more chiral carbons | - stereoisomers that are not mirror images

Question 31

formula for the maximum amount of stereoisomers

Answer 31

2^n

Question 32

diastereomers have different

Answer 32

physical properties

Question 33

how can enantiomers be separated?

Answer 33

turn into diastereomers through chemical resolution

Question 34

describe chemical resolution?

Answer 34

react the racemic mixture with a pure chiral compound

Question 35

alkyl halides are

Answer 35

halogens directly bonded to a carbon

Question 36

alkyl vinyl are

Answer 36

halogens bonded to a carbon with a double bond

Question 37

aryl halides are

Answer 37

halogens bonded to a carbon w/ a benzene ring

Question 38

halogens are more ________ than carbon

Answer 38

electronegative

Question 39

when a carbon is attacked by a nucleophile the halogen can leave with

Answer 39

the electron pair

Question 40

CH2X2 is called

Answer 40

methylene HALIDE

Question 41

CHX3 is called

Answer 41

HALOform

Question 42

CX4 is a

Answer 42

carbon tetraHALIDE

Question 43

what are the 2 types of dihalides?

Answer 43

geminal and vicinal

Question 44

geminal halides are

Answer 44

two halogens bonded to the same carbon

Question 45

vicinal halides are

Answer 45

two halogens bonded to adjacent carbons

Question 46

for halides greater intermolecular forces indicate

Answer 46

higher b.p.

Question 47

greater mass in halides indicate...

Answer 47

higher b.p.

Question 48

spherical shape in halides decreases

Answer 48

boiling point

Question 49

alkyl chlorides/ fluorides with a single carbon are

Answer 49

less dense than water

Question 50

alkyl chlorides with 2 or more chlorines are

Answer 50

more dense then water

Question 51

alkyl bromides and iodides are

Answer 51

more dense than water

Question 52

bromination is highly selective:

Answer 52

3>2>1