✅18 - Organic Chemistry III Flashcards

1
Q

What are aromatic compounds?

A

Compounds containing a hydrocarbon ring containing delocalised electrons

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

What are aliphatic compounds?

A

Ones which do not have a hydrocarbon ring with delocatised electrons

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

What is benzene described as?

A

An arene

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

What are the physical properties of benzene?

A

A colourless liquid
Boiling temperature of 80 degrees
Insoluble in water

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

What is the molecular formula of benzene?

A

C6H6

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

What is the Kekule structure of benzene?

A

Alternating double and single bonds in a cyclic structure with a ring of hydrogen around it

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

How does bromine water disprove the Kekule structure?

A

If benzene contained three C=C bonds, it would readily decolourise bromine water, but it does not, suggesting there are no double bonds

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

How do the isomers of dibromobenzene disprove the Kekule structure?

A

If the Kekule structure is correct, there would be four isomers of dibromobenzene, however only three are known to exist as there are no C=C bonds

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

How do bond lengths disprove the Kekule structure?

A

C-C bonds and C=C bonds are different lengths, but in benzene the bonds lengths are all the same, so there cannot be different types of bonds in the molecule

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

How do enthalpy changes of hydrogenation disprove the Kekule structure?

A

The actual enthalpy change of hydrogenation of benzene differs from the theoretical value for if it had C=C double bonds

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

What are the four factors which disprove the Kekule structure?

A

Bromine water
Isomers of dibromobenzene
Bond lengths
Enthalpy change of hydrogenation

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

In the actual structure of benzene how are the electrons aranged?

A

In two delocalised rings, one above and one above the Carbon ring, of pi electrons

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

What are the conditions needed for hydrogenation of benzene?

A

Hydrogen, and heating under pressure with a nickel catalyst

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

What is the equation for the hydrogenation of benzene?

A

C6H6 + 3H2 ——> C6H12

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

What type of flame does benzene give?

A

A smoky flame

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

What are halogen carriers?

A

Usually metal-halogen compounds such as aluminium chloride

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

What are the products of bromination of benzene?

A

Bromobenzene and hydrogen bromide

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

What is nitration of benzene?

A

The substitution of a hydrogen atom by a nitro group, NO2

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

What are the conditions needed for nitration of benzene?

A

Warming it with a mixture of conc nitric acid and sulfuric acid catalyst

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

What are the products of nitration of benzene?

A

Nitrobenzene and water

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

What are two of the types of Friedel-Crafts reactions?

A

Alkylation and acylation

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

What are the features all Friedel-Crafts reactions have in common?

A

Using reagent XY, one of the hydrogens In benzene is substituted by Y, and the other product is HX
A catalyst is needed
Anyhydrous conditions are needed because water would react with catalyst and organic product

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

What is an alkyl group?

A

CH3

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

What is an acyl group?

A

COCH3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the reactant for alkylation of benzene?

A

A halogenalkane, such as CH3Cl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the products of alkylation of benzene?

A

An alkylbenzene such as methylbenzene and hydrogen chloride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the products of the acylation of benzene?

A

A ketone (phenylethanone) and hydrogen chloride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What name is often used when the benzene ring is attached of another functional group?

A

Phenyl or phen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What makes benzene act as an electrophile?

A

The delocalised electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does Bromine react with the catalyst in Bromination of Benzene?

A

It forms Br+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the equation for the reaction between Bromine and the halogen carrier in Bromination?

A

AlCl3 + Br2 ——> Br+ + AlCl3Br-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What are the inorganic products formed in the bromination of benzene?

A

AlCl3 and HBr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the first step in Nitration of Benzene?

A

Formation of an electrophile through nitric acid and sulfuric acid reacting to form NO2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the equation for the reaction to form an electrophile?

A

HNO3 + H2SO4 ——> NO2+ HSO4- +H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What type of mechanism is Alkylation of benzene?

A

Electrophillic substitution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the inorganic products in alkylation?

A

HCl and AlCl3

37
Q

What are the organic products in acylation?

A

HCl and AlCl3

38
Q

What does Friedel-Crafts Acylation produce?

A

Phenylketones

39
Q

What is benzene refluxed with in acylation?

A

An acyl chloride

40
Q

What must the temperature be kept below for nitration of benzene?

A

55 degrees C

41
Q

What happens if the temperature is above 55 for nitration of benzene?

A

Multiple substitutions occur

42
Q

Why is phenol more reactive than benzene

A

The OH group makes it more likely to undergo electrophillic substitution
One of the lone pairs in oxygen p orbital becomes delocalised, increasing electron density of the ring

43
Q

What happens if you shake phenol with bromine water?

A

It decolourises it

44
Q

Why does substitution occur more than once on phenol?

A

The OH group makes it very attractive to electrophiles

45
Q

What can aspirin be synthesised from?

A

Salicylic acid and ethanoic anhydride

46
Q

What is the amine functional group?

A

-NR2, where R is an alkyl group or hydrogen

47
Q

What can aliphatic amines be made from?

A

Halogenoalkanes or nitriles

48
Q

What are amines?

A

Weak bases, as they accept protons

49
Q

What does the strength of the amine base depend on?

A

How available the nitrogen’s lone pair of electrons is

50
Q

What is the order of basicity?

A

Primary aromatic amine < Ammonia < Primary aliphatic amine

51
Q

Why are the aliphatic amines the strongest bases?

A

The distribution of negative charge is distributed entirely on the lone pair, whereas in the aromatic amine it is distributed widely

52
Q

What are small amines soluble in?

A

Water, as the amine group can form hydrogen bonds with the water molecule

53
Q

The bigger the amine the greater the…

A

…London forces

54
Q

What kind of solutions do amines form?

A

Alkaline

55
Q

What do amines form with Copper (II) ions?

A

Complex ions

56
Q

What complexes do Cu2+ ions form with water?

A

[Cu(H2O)6]2+ - a blue solution

57
Q

What complex is formed if a small amount of butylamine solution is added?

A

[Cu(OH)2(H2O)4] - a blue precipitate

58
Q

If more butylamine solution is added, how does the complex change?

A

[Cu(CH3(CH2)3NH2)4(H2O)2]2+ - a deep blue solution

59
Q

How do amines react with halogenoalkanes?

A

In nucleophillic substitution reactions

60
Q

How can N-Substituted Amides be made from amines?

A

By acetylation

61
Q

Amides are…

A

…carboxylic acid derivatives

62
Q

What is the amide functional group?

A

-CONH2

63
Q

Why do amides behave differently from amines?

A

Because the carbonyl group pulls electrons away from the rest of the group

64
Q

What suffix do amides have?

A

-amide

65
Q

What can amides be made from?

A

Acyl chlorides

66
Q

What are the reactants needed to make a primary amide?

A

An acyl chloride and concentrated ammonia

67
Q

What reactants are needed to make an N-substituted amide?

A

An acyl chloride and primary amine

68
Q

What is an N-substituted amide?

A

One of the hydrogens in NH2 is substituted with an alkyl group

69
Q

What are amide links?

A

-CONH-

70
Q

What reacts to form an amide link?

A

-COOH and -NH2

71
Q

Which two types of molecule form a polyamide?

A

Dicarboxylic acids and diamines

72
Q

What are proteins?

A

Condensation polymers of amino acids

73
Q

What is needed to hydrolyse a protein into amino acids?

A

6moldm-3 hydrochloric acid and reflux

74
Q

Which two types of molecule form a polyester?

A

Dicarboxylic acids and diols

75
Q

What is an ester link?

A

-COO-

76
Q

What functional groups do amino acids have?

A

NH2 and COOH

77
Q

What is a zwitterion?

A

An overall neutral molecule that has a positivie and negative charge on different parts of the molecule

78
Q

In acidic conditions, which part of the amino acid is changed?

A

The NH2 becomes protonated, forming NH3+

79
Q

What charges does the amino acid have at its isoelectric point?

A

The NH2 becomes NH3+ and the COOH becomes COO-

80
Q

In alkaline conditions, which part of the amino acid is changed?

A

The COOH group becomes COO-

81
Q

Most amino acids are…

A

…chiral

82
Q

What can be used to identify unknown amino acids?

A

Paper chromatography

83
Q

How would you calculate an Rf value?

A

Distance travelled by spot/distance travelled by solvent

84
Q

What is the general formula of a Gringard reagent?

A

RMgX

85
Q

How are Gringards reagents made?

A

By refluxing a halogenoalkane with magnesium in dry ether

86
Q

What would a Gringard’s reagent + CO2 form?

A

A carboxylic acid

87
Q

What are the conditions needed to form a carboxylic acid from Gringards and CO2?

A

Dry ether and dilute HCl

88
Q

What do Gringards form in reaction with aldehydes and ketones?

A

Alcohols

89
Q

What are the conditions needed to form an alcohol from Gringards + carbonyl?

A

Dry ether and dilute HCl