Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

chemistry > aromatic compounds and amines/further analysis > Flashcards

aromatic compounds and amines/further analysis Flashcards

(59 cards)

Start Studying
1
Q

name of way the electrons are arranged in benzene

A

π

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

difference between addition and electrophilic substitution of benzene

A

addition does not restore aromaticity

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

give an example of addition of benzene

A

hydrogenation

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

equation of hydrogenation

A

benzene + 3H2 -> C6H12 (cyclohexane)

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

define alkylation

A

addition of alkyl group to benzene ring

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

which positions undergo substitution (on alkylarenes)? why?

A

2 or 4, electron donation activates these positions

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

meaning of excess reactant with benzene

A

multiple substitutions

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

why is freidel crafts used in organic synthesis?

A

to make compounds more reactive

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

reaction conditions for acyl and alkyl friedel crafts

A

anhydrous AlCl3 catalyst

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

use of acylated benzene rings

A

dyes

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

products of reaction of reactant with AlCl3 to make electrophile

A

[X]+ + [ALCL4]- (e;ectrophile)
where X is the other reactant

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

conditions for hydrogenation of benzene

A

Pt/Ni catalyst
heat

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

conditions for oxidation of benzene

A

hot alkaline KMnO4 and dilute acid

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

catalyst for halogenation of benzene

A

AlCl3/AlBr3

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

name three ways to prepare amines

A

haloalkanes + ammonia
reduction of nitriles
(aromatic) nitrated benzene + NaOH

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

what happens during reduction of nitriles?

A

-CN group reduced (gain of electrons/hydrogen) to NH2

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

conditions and reactants of reduction of nitriles

A

gas of H2 and nitriles passed over nickel catalyst or LiAlH4

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

equation of reduction of nitriles

A

CH3CN + 4[H]/2H2 -> CH3CH2NH2

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

4 steps of formation of aromatic amines

A
  • nitration of benzene
  • reduced with hot tin and cold Hal under refiux
  • NaOH added to make phenyl amine
  • distilled (remove water_
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

conditions for nucleophilic substitution of ammonia

A

hot ethanolic under pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

why is reacting haloalkanes with ammonia not very good for making amines

A

many subs occur, difficult to make just the desired product

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how to make only one substitution occur (form primary amine)

A

large excess of ammonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how can an amine act as a bronsted lowry base?

A

donating a lone pair of electrons to form dative bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

advantage of polarity of amines

Study These Flashcards
A

water solubility

25
equation for amine as base
RNH2 + HCL -> [RNH3+][Cl-]
26
what effects strength of amines to be a base
ability of lone pair to accept a proton
27
what is the positive inductive effect
some groups on an amine donate electron density so lone pair is more available
28
what groups contribute to delocalisation effect
benzene rings
29
how does delocalisation effect ability go an amine to be a base
draw electrons away from N so lone pair less readily available
30
equation for nucleophillic sub of amines
RCH2X + 2NH3 -> RCH2NH2 + NH4X
31
how to make nitriles?
haloalkane + KCN and aqueous alcohol
32
catalyst for reduction of nitriles
nickel
33
equation for dissociation of amines
RNH2 + H20 <-> RNH3+ + OH-
34
signs of impurities from boiling points
melts over a range of temperatures melts too early (lower temp)
35
why does cyclohexa-1,4-diene have an enthalpy of hydration less exothermic than that of cyclohexa-1,3-diene?
double bonds closer together in 1,3 pool of high delocalised electron density more energy to overcome bonds
36
calibration for NMR
TMS Si(CH3)4
37
why is TMS used to calibrate NMR
- only one hydrogen environment, used as 0 - non toxic - inert - easy to remove (low b.pb/volatile)
38
use of CDCl3 in NMR
solvent polar molecules no hydrogens
39
use of CCl4 in NMR
solvent non polar molecules no hydrogens
40
thin layer chromatography
stationary phase - thin metal sheet + Al2O3 or SiO2, absorbs sample, moves different distances depending on strength of bonds between molecule and stationary phase mobile phase - polar (water or alcohol) or non polar (alkanes) see spots with UV, ninhydrin (carcinogen) or iodine vapour
41
column chromatography
long vertical glass tube stationary phase = inert solid mobile phase = liquid solvent stationary phase completely absorbed in mobile phase sample mixture is dissolved in solvent and pu in top of column fresh solvent (eulent) consistently added to stop it drying gravity pulls components down, molecules with highest attraction ti stationary phase take the most time to move down time measures by sight (e.g. if coloured) or with UV light
42
proof that benzene is more stable than theoretical cylclyhexa-1,3,5-triene?
you'd expect an enthalpy of hydration to be -360 but it is -208 152kJmol-1 less exothermic than expected less energy released than expected must be stored in bonds benzene is more stable
43
use of quaternary ammonium compounds
cationic surfactants
44
what are cationic surfactants
conditioners
45
amide functional group
-CONH2
46
reaction to make NO2+ ion during nitration
HNO3 + H2SO4 -> HSO4- + NO2+ + H2O
47
role of sulphuric acid during nitration
catalyst
48
role of NO2+ ion during nitration
electrophile
49
how to ensure only one sub during nitration
keep below 55 degrees
50
use of nitration reaction
TNT
51
mechanism benzene undergoes
electrophillic sub
52
effect of benzene ring on strength of base
draw electrons away from nitrogen atom weaker base
53
effect of alkyl group on strength of base
postive inductive effect 'donates' electrons stronger base
54
acyl chloride + ammonia
[primary amide]+ + [Cl]-
55
primary amide + Cl-
n subbed amide + HCl
56
nitrated benzene -> aromatic amine
Sn, conc HCl, reflux NaOH
57
gas chromatography
coiled to safe space stationary phase - solid (may be coated in oil) mobile phase - inert gas each component takes a different amount of time to be detected at end
58
difference + simiralities between delocalisation model and kekules
both overlap in p-orbitals pi system above and below plane different kekule has overlapping pi orbitals but delocalised has all overlapping
59
why is cycle-1,3-triene more stable than cyclo-1,4-triene?
pi orbital overlap in 1,3 because bonds are closer together

chemistry (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions