Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OChem II > Chapter 19 - Benzene & Aromatic Compounds > Flashcards

Chapter 19 - Benzene & Aromatic Compounds Flashcards

1
Q

Benezene formula

A

C6H6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Benzene + Br2

A

No Rxn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Benzene + Br2 + catalyst

A

Substitution Reaction
C6H5Br + HBr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

2 benzene rings bonded

A

naphthalene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

3 benzene rings bonded

A

phenanthrene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

phenanthrene

A

3 benzene rign

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

3 benzene rings bonded

A

phenanthrene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

phenanthrene

A

3 benzene rings bonded together.
Carcinogen foundin cigarettes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

3 criteria to be aromatic

A

1- cyclic
2 - planar
3 - compeletely conjugated
4 - odd number of pi electron pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The pi cloud must have an ___ number of pairs of pi electrons

A

odd

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

criteria for antiaromatic compounds

A

1 - cyclic
2 - planar
3 - every ring atom must have a p orbital
4 - even number of pi electron pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

C5H5N

A

pyridine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

pyridine

A

C5H5N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Is pyridine aromatic or not?

A

Aromatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

furan
forumula + aromatic?

A

C4H4O

aromatic b/c it can rehybridize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

pyrrole
forumula + arromatic?

A

C4H4NH

aromatic because it can rehybridize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what does rehybridization allow for?

A

it allows an sp3 hybrid to become an sp2 hybrid so that a compound may be aromatic and more stable.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

annulene

A

hydrocarbons containing a single ring with alternating single and double bonds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

[6]-annulene AKA

A

benzene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How to tell if one ring is more acidic than another?

A

the conj. base (product after a hydrogen is removed) will be aromatic and therefore stable. This means the starting material is acidic.

21
Q

How to tell if one ring is more basic than another?

A

the conj. acid (product after a hydrogen is added) will be aromatic and therefore more stable. This means the startic material is basic.

22
Q

How to tell if one ring is more basic than another?

A

the conj. acid (product after a hydrogen is added) will be aromatic and therefore more stable. This means the startic material is basic.

23
Q

Why does benzne do substitution reactions and not addition reactions?

A

If benzene participates in an addition reaction, it looses its aromaticity and is therefore more unstable.

Whereas if it participates in a substitution rxn in stead, it maintains it aromaticity and stability.

24
Q

What is the difference between Y- acting as a a nucleophile and Y- acting as a base in aromatic reactions?

A

If it were to react as a nucleophile it would add to the benezene ring and cause it to lose its aromaticity.

If it acts as a base, it removes an H and reforms the double bond, maintianing aromaticity and stability.

25
Q

Expected vs Actual energy difference b/w benzene and cyclohexane

A

Expected -360
Actual -208

26
Q

cycloalkene + Br2

A

vicinal dibromide
(anti-addition prouduct)

proceeds through electrophilic addition

27
Q

benzene + Br2

A

no reaction

28
Q

beneze + Br2 + FeBr3

A

bromobenzene

(electrophilic aromatic substitution)

29
Q

What catalyst is typically used to react benzene with bromine?

A

FeBr3

30
Q

What type of catalyst does FeBr3 act as?

A

lewis acid catalyst

31
Q

What is the rds in electrophilic aromatic subsitution?

A

the 1st step where the aromatic ring is openened

32
Q

Nucleophiles attack ________.

A

electrophiles

33
Q

Bases attack ________.

A

hydrogens

34
Q

nitric acid

A

HNO3

35
Q

sulfuric acid

A

H2OS4

36
Q

What are the 2 main mechanistic steps in electrophilic aromatic substitution?

A

1 - Generation of the Reactive Electrophile
2 - Rxn b/w the E+ and benzene

37
Q

Electrophile for Halogenation of Benzene

A

Br+ or Cl+

38
Q

Electrophile for Nitration of Benzene

A

NO2+

39
Q

Electrophile for Sulfonation of Benzene

A

HSO3

40
Q

Catalyst for halogenation of benzene

A

FeBr3 or FeCl3

41
Q

Reagents for Bromination of Benzene

A

Br2
FeBr3

42
Q

Reagents for Chlorination of Benzene

A

Cl2
FeCl2

43
Q

Reagents for Nitration of Benzene

A

HNO3
H2SO4

44
Q

Reagents for Sulfonation of Benzene

A

SO3
H2SO4

45
Q

Reagents for Acylation of Benzene

A

Acid Chloride
AlCl3

46
Q

Reagents for Alkylation of Benzene

A

Cl-R
AlCl3

47
Q

When forming the electrophile for nitration of benzene, _______ acts as a base because ___________ is a stronger acid.

A

Nitrous Acid acts as a Base

Because Sulfuric Acid is a Stronger Acid

48
Q

What acts as a good leaving group in the formation of the electrophile for nitration of benzene?

A

H2O

49
Q

Acylation and Alkylation lead to the formation of __ - ___ bonds

A

Carbon-Carbon

OChem II (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions