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A level Chemistry > Unit 4.5 - Carboxylic acids and their derivatives > Flashcards

Unit 4.5 - Carboxylic acids and their derivatives Flashcards

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1
Q

General formula of carboxylic acids + explain

A

RCOOH
R is a hydrogen, alkyl group or aromatic group

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2
Q

What functional group do carboxylic acids?

A

The carboxylic one

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3
Q

How are carboxylic acids named?

A

By adding the suffix -oic acid to the alkane stem

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4
Q

Compare the infrared spectrums of alcohols and carboxylic acids

A

Alcohol = broad OH peak
Carboxylic acid = peak is broader with an additional sharp peak due to the carbonyl group

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5
Q

Another word for ethanoic acid

A

Formic acid

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6
Q

Another word for acetic acid

A

Ethanoic acid

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7
Q

Another word for benzene carboxylic acid

A

Benzoic acid

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8
Q

Formic acid

A

methanoic acid

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9
Q

Acetic acid

A

Ethanoic acid

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10
Q

benzoic acid

A

Benzene carboxylic acid

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11
Q

Benzoic acid shortened structural formula

A

C6H5COOH

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12
Q

What happens in the derivatives of carboxylic acids?

A

The -OH group is replaced by other functional groups

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13
Q

Derivative if the OH group in a carboxylic acid is replaced with Cl

A

Acid chloride

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14
Q

Derivative if the OH group in a carboxylic acid is replaced with OR’

A

Ester

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15
Q

How do you get an ester?

A

React an alcohol with a carboxylic acid

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16
Q

Derivative if the OH group in a carboxylic acid is replaced with -OCOR’

A

Acid anhydride

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17
Q

What’s the only acid anhydride that we deal with?

A

Ethanoic anhydride

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18
Q

Derivative if the OH group in a carboxylic acid is replaced with NH2

A

Amide

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19
Q

Amide functional group

A

-NH2

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20
Q

Acid anhydride functional group

A

-OCOR’

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21
Q

Derivative if the OH group in a carboxylic acid is replaced with C———N

A

Nitrile

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22
Q

Nitrile functional group

A

C=—N (triple bond)

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23
Q

Why is it strange that nitriles are classed as carboxylic acid derivatives?

A

Since the nitrile functional group hasn’t replaced any OH’s

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24
Q

Ethyl ethanoate shortened structural formula

A

CH3COOCH2CH3

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25
Q

CH3COOCH2CH3

A

Ethyl ethanoate

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26
Q

Methyl butanoate

A

CH3CH2CH2COOCH3

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27
Q

CH3CH2CH2COOCH3

A

Methyl butanoate

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28
Q

Ethanoyl chloride

A

CH3COCl

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29
Q

CH3COCl

A

Ethanoyl chloride

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30
Q

Propanoyl chloride

A

CH3CH2COCl

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31
Q

CH3CH2COCl

A

Propanoyl chloride

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32
Q

Ethanamide

A

CH3CONH2

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33
Q

CH3CONH2

A

Ethanamide

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34
Q

But an aide

A

CH3CH2CH2CONH2

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35
Q

CH3CH2CH2CONH2

A

Butanamide

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36
Q

Propanenitrile

A

CH3CH2CN

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37
Q

CH3CH2CN

A

Propanenitrile

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38
Q

Ethanoic anhydride

A

(CH3CO)2O

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39
Q

(CH3CO)2O

A

Ethanoic anhydride

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40
Q

Aspirin

A

Ethanoic anhydride

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41
Q

Methyl benzene carboxylate

A

C6H5COOCH3

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42
Q

C6H5COOCH3

A

Methyl benzene carboxylate

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43
Q

Sodium butanoate

A

CH3CH2CH2CH2COONa

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44
Q

CH3CH2CH2COONa

A

Sodium butanoate

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45
Q

2-hydroxyethanoic acid

A

CH2OHCOOH

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46
Q

CH2OHCOOH

A

2-hydroxyethanoic acid

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47
Q

Where is “1” whenever deciding on the position of a different functional side group on a carboxylic acid?

A

Wherever the carboxylic acid carbon is

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48
Q

What is it if OH- is directly bonded to a benzene?

A

Phenol, not an alcohol

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49
Q

What have the same molecular structures?

A

Esters and carboxylic acids

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50
Q

What can we do since esters and carboxylic acids have the same molecular structures?

A

Can work out their structural isomers

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51
Q

What’s the same between esters and carboxylic acids?

A

Same molecular structures

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52
Q

How do we work out the possibly isomers of an ester?

A

Write it out, work out the molecular formula and remember that the isomers can be esters and carboxylic acids

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53
Q

Methods of preparing carboxylic acids

A

Oxidation of primary alcohols
Hydrolysis of nitriles
Hydrolysis of amides
Preparation of aromatic carboxylic acids

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54
Q

How are carboxylic acids prepared from the oxidation of primary alcohols?

A

The alcohol is refluxed with acidified potassium dichromate (VI)

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55
Q

Explain the two routes in which a carboxylic acid can be formed from primary alcohols

A

Mildly oxidised with acidified potassium dichromate (VI) to give an aldehyde and then reflux with more acidified potassium dichromate (VI) to give a carboxylic acid
Or, just reflux initially with acidified potassium dichromate (VI) to give a carboxylic acid

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56
Q

What happens during he hydrolysis of nitriles

A

The nitrile is refluxed with dilute HCl/aqueous NaOH

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57
Q

Give the equation for the hydrolysis of Propanenitrile with dilute HCl

A

CH3Ch2CN ——> CH3CH2COOH + NH4Cl

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58
Q

What is the better route to use when undergoing the hydrolysis of nitriles?

A

To use aqueous sodium hydroxide

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59
Q

Why is it a better route to use aqueous sodium hydroxide for the hydrolysis of nitriles?

A

Since a salt of the acid is formed

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60
Q

Describe the reaction of the hydrolysis of nitriles using aqueous NaOH

A

With sodium hydroxide, the sodium salt is formed. A strong acid (HCl) is added in order to form the acid. The HCl releases the acid from the salt to become a free acid.

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61
Q

What does adding HCl to the sodium salt during the hydrolysis of nitriles do?

A

It releases the acid from the salt to become a free acid

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62
Q

Free acids

A

Released from the salt

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63
Q

Name for acids released from a salt

A

Free acids

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64
Q

Equation for the hydrolysis of Propanenitrile using aqueous sodium hydroxide

A

CH3Ch2CN —> (adding NaOH) CH3Ch2COONa + NH3 —> (adding HCl) CH3CH2COOH

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65
Q

Describe the hydrolysis of amides to prepare carboxylic acids

A

The amide is refluxed with dilute HCl/aqueous sodium hydroxide and the course of the reactions is similar to that with nitriles

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66
Q

Give the equation for the hydrolysis of Ethanamide with aqueous sodium hydroxide

A

CH3CONH2 —> (adding NaOH) CH3COONa + NH3 —> (adding HCl) CH3CH2COOH

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67
Q

Equation for the hydrolysis of Ethanamide with HCl

A

CH3CONH2 —> CH3COOH + NH4Cl

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68
Q

How are aromatic compounds formed differently to aliphatic ones?

A

They have a different oxidising agent

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69
Q

What is benzene not oxidised by and why?

A

Potassium manganate (VII) since it’s aromatic with no methyl side group

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70
Q

When can oxidation of benzene occur?

A

When there’s a methyl side group on the benzene ring

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71
Q

How is an aromatic carboxylic acid formed from methyl benzene?

A

When refluxed with an alkaline (in sodium carbonate) potassium manganate (VII) and the mixture subsequently acidified, an aromatic carboxylic acid is formed

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72
Q

Type of potassium manganate (VII) needed to acidify methyl benzene

A

Alkaline (in sodium carbonate)

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73
Q

Alkaline potassium manganate (VII)

A

In sodium carbonate

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74
Q

What is formed when methyl benzene is refluxed with alkaline (in sodium carbonate) potassium manganate (VII) and the mixture subsequently acidified?

A

Benzene carboxylic acid

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75
Q

How is the free acid formed during the acidification of methyl benzene?

A

By adding HCl

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76
Q

What type of alkaline needs to be used to make potassium manganate (VII) alkaline for the preparation of benzene carboxylic acid?

A

Hot sodium carbonate

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77
Q

What type of benzene do we oxidise to form an aromatic carboxylic acid?

A

An alkyl benzene

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78
Q

Describe the boiling points of carboxylic acids

A

The lower homologues are liquids with boiling points considerably higher than that of alkanes of similar molar mass

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79
Q

What type of bonds can carboxylic acids form with each other?

A

Hydrogen

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80
Q

How come carboxylic acids can form hydrogen bonds with each other?

A

Due to the presence of the OH group

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81
Q

Why do carboxylic acids have boiling points considerably higher than that of alkanes of similar molar mass?

A

Because they form hydrogen bonds between each other, which require more energy to break that just the Van der Waal forces in alkanes

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82
Q

What type of carboxylic acids have higher boiling points than alkanes of similar molar mass?

A

The lower homologues

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83
Q

What are the lower homologues of carboxylic acids soluble in?

A

Polar solvents such as water and non-polar solvents such as benzene

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84
Q

What type of carboxylic acids are soluble in polar solvents such as water but also non-polar solvents such as benzene?

A

Lower homologues

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85
Q

Why are lower homologues of carboxylic acids soluble in polar solvents such as water?

A

Due to the presence of C=O and OH groups - forms hydrogen bonds

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86
Q

What type of solvent is benzene?

A

Non-polar

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87
Q

Name a non-polr solvent

A

Benzene

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88
Q

Why are lower homologues of carboxylic acids soluble in non-polar solvents such as benzene?

A

Due to the presence of the hydrocarbon chin

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89
Q

What happens to the solubility of the carboxylic acid as the chain length increases?

A

Decreases

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90
Q

What property of a carboxylic acid can affect its solubility?

A

Chain length

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91
Q

Why does the solubility of carboxylic acids decrease as the chain length increases?

A

The contribution of hydrogen bonding becomes less effective as the size of the hydrocarbon chain increases- there are more non-polar groups which outweigh the polar groups

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92
Q

Chemical reactions of carboxylic acids to remember

A

Acidity
Reduction - (lithium aluminium hydride)
Decarboxylation
Esterification
Formation of acid chlorides

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93
Q

What type of acids are carboxylic acids?

A

Weak ones

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94
Q

Weak acid

A

Only partially dissociated into its ions in solution

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95
Q

How do we know that carboxylic acids are weak acids in aqueous solution?

A

About 1-2% of the molecules are dissociated into their ions

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96
Q

Carboxylic acids dissociating into their ions in aqueous solution

A

CH3COOH + H2O —><— CH3COO- + H3O+

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97
Q

What do carboxylic acids do with blue litmus? Why?

A

Turn it red
pH < 7

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98
Q

How do we know that carboxylic acids are weak acids

A

Turn blue litmus red, pH<7
Release carbon dioxide gas with carbonates and hydrogen carbonates

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99
Q

What happens when carboxylic acids react with carbonates and hydrogencarbonates?

A

They release CO2 gas

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100
Q

Equation for the reaction between sodium carbonate and ethanoic acid

A

Na2CO3 + 2CH3COOH —> 2CH3COONa + CO2 + H2O

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101
Q

What are the only things that react with carbonates and hydrogen carbonates to give a salt, CO2 and H2O?

A

Carboxylic acids

102
Q

Which reaction is used as a test for carboxylic acids?

A

React with carbonates and hydrogen carbonates

103
Q

Observation for a positive test for a carboxylic acid with a carbonate or hydrogencarbonate

A

Effervescence
Lime water turns milky

104
Q

Lime water

A

Calcium hydroxide

105
Q

Calcium hydroxide

A

Limewater

106
Q

Describe the salts of carboxylic acids

A

Ionic substances
High melting points
Tend to be soluble in water

107
Q

List the following in terms of acidic strength:
Phenol, water, ethanoic acid, methanol

A

(Weakest first)
Methanol
Water
Phenol
Ethanoic acid

108
Q

Ka from pKa

A

Ka = 10^-pKa

109
Q

pKa from Ka

A

pKa = -log10(Ka)

110
Q

How do we identify the strength of an acid in terms of pKa?

A

Lower pKa = stronger

111
Q

How do we identify the strength of an acid in terms of Ka?

A

Higher Ka = stronger

112
Q

What is the acidity of the compounds methanol, water,phenol and ethanoic acid largely dependent on?

A

The stability of the anion

113
Q

How is an anion stabilised?

A

By the delocalisation of the negative charge on the anion

114
Q

Explain how the acidity of compounds depends on the stability of the anion?

A

An anion is stabilised by delocalisation of the negative charge on the anion. Thus, the greater the delocalisation of the negative charge, the most stable will be the anion and the greater will be the acidic strength of the compound.

115
Q

What does greater delocalisation of the negative charge on an anion lead to?

A

A more stable anion and the greater the acidic strength of the compound

116
Q

What does a more stable anion lead to?

A

Greater acidic strength of the compound

117
Q

How does a compound have greater acidic strength?

A

By having a More stable anion

118
Q

How is an anion more stable?

A

With greater delocalisation of the negative charge

119
Q

Explain why methanol and water are very weak acids

A

There is no delocalisation
There is no anion

120
Q

Why is methanol a weaker acid than water?

A

The methyl group decreases the effect of the negative charge on the oxygen, making it a weaker acid than the water.

121
Q

Explain why phenol is a stronger acid than water

A

The negative charge on the anion is partially delocalised into the ring which stabilises the negative charge

122
Q

Explain why ethanoic acid is a stronger acid than phenol

A

In ethanoic acid, the negative charge is delocalised to a considerable extent in the ethanoate ion. This makes ethanoic acid a stronger acid than phenol as the extent of anion stabilisation due to delocalisation is greater.

123
Q

How are anions stabilised?

A

By delocalisation

124
Q

what does delocalisation do to anions?

A

Stabilises them

125
Q

What will the anion from phenol react with and what won’t it react with?

A

Will react with sodium hydroxide
Not with sodium carbonate

126
Q

What will the anion from phenol do with neutral iron (III) chloride?

A

Will give a violet colourisation

127
Q

What will an anion from a carboxylic acid react with?

A

Sodium hydroxide and sodium carbonate solution

128
Q

What will an anion from a carboxylic acid do with neutral iron (III) chloride?

A

Will not give a violet colourisation

129
Q

What do phenols give a violet colourisation in?

A

Neutral iron (III) chloride

130
Q

Are carboxylic acids readily reduced? How do you know?

A

No
They’re not reduced by NaBH4

131
Q

How are carboxylic acids reduced?

A

With lithium aluminium hydride

132
Q

What are carboxylic acids reduced to with lithium aluminium hydride?

A

Primary alcohols

133
Q

Conditions for carboxylic acids being reduced with lithium aluminium hydride to primary alcohols

A

The acid is reacted with LiAlH4 dissolved in ether at room temperature
The reaction must be carried out under dry conditions as LiAlH4 reacts violently with water

134
Q

Why must the reduction of carboxylic acids be done under dry conditions?

A

As LiAlH4 reacts violently with water

135
Q

Equation for the reduction of ethanoic acid

A

CH3COOH + 4[H] (from LiAlH4) ——> CH3CH2OH

136
Q

What happens during a decarboxylation reaction?

A

The carboxylic acid loses the elements of CO2

137
Q

What is formed after the decarboxylation of a carboxylic acid?

A

An alkane or an aromatic hydrocarbon

138
Q

Describe the alkane formed after the decarboxylation of a carboxylic acid

A

Has one less carbon than the carboxylic acid

139
Q

How is the carboxylic acid treated for its decarboxylation to occur?

A

The carboxylic acid or more conveniently, its sodium salt, is heated with soda-lime [Ca(OH)2/NaOH]

140
Q

Soda-lime + what reaction of carboxylic acids is it used for?

A

[Ca(OH)2/NaOH]
Decarboxylation

141
Q

Decarboxylation of CH3COOH equation

A

CH3COOH ————> CH4
[Ca(OH)2/NaOH]

142
Q

Decarboxylation of CH3CH2COOH equation

A

CH3CH2COOH ———> CH3CH3
[Ca(OH)2/NaOH]

143
Q

What is decarboxylation usually carried out using and why?

A

Using the sodium salt of the acid rather than the acid itself as it’s generally more effective

144
Q

What can we use to represent the equinox for decarboxylation using soda lime?

A

Using calcium hydroxide, calcium oxide or sodium hydroxide

145
Q

Conditions for the esterification of a carboxylic acid

A

Heated in the presence of concentrated sulfuri acid
Refluxed

146
Q

Describe and explain the process of esterification in the absence of sulfuric acid

A

Very slow
Concentrated sulfuric acid is a dehydrating agent, removing water from the equilibrium mixture. The position of equilibrium goes to the right and the reaction goes to completion.

147
Q

Equation for the esterification of CH3COOH

A

CH3COOH + CH3CH2OH —><— CH3COOCH2CH3 + H2O

148
Q

What are the reagents that can be used to make acid chlorides?

A

Phosphorus trichloride PCl3
Phosphorus pentachloride PCl5
Sulphur dichloride oxide SOCl2

149
Q

What can the following reagents be used for?
Phosphorus trichloride PCl3
Phosphorus pentachloride PCl5
Sulphur dichloride oxide SOCl2

A

Making acid chlorides

150
Q

Explain the process of making acid chlorides with PCl5 as the reagent

A

The reaction takes place by reacting a carboxylic acid with phosphorus (v) chloride at room temperature under anhydrous conditions - as both phosphorus (v) chloride and the product ethanoyl chloride react violently with water
Since HCl gas is released in the reaction, the preparation must be carried out in a fume cupboard

151
Q

Why must the reaction of the formation of acid chlorides with PCl5 be carried out under anhydrous conditions and in a fume cupboard?

A

Anhydrous conditions —> both PCl5 and the product ethanoyl chloride react violently with water
Fume cupboard —> as HCl gas is released in the reaction

152
Q

Equation for the reaction between ethanoic acid and PCl5

A

CH3COOH + PCl5 ——> CH3COCl + POCl3 + HCl

153
Q

Equation for the reaction between ethanoic acid and PCl3

A

3CH3COOH + PCl3 —> 3CH3COCl + H3PO3

154
Q

What is the preferred reagent to be used for the production of acid chlorides?

A

SOCl2

155
Q

Gaseous coproducts when forming acid chlorides with SOCl2

A

SO2 and HCl

156
Q

Equation for the reaction between ethanoic acid and SOCl2

A

CH3COOH + SOCl2 —> CH3COCl + SO2 + HCl

157
Q

Stages for the formation of amides from carboxylic acids

A
  1. The carboxylic acid is initially reacted with dilute aqueous ammonia. In this reaction the salt ammonium ethanoate is formed.
  2. When the mixture is heated, the salt loses water and an amide is formed.
158
Q

Equations for the formation of an amide from CH3COOH

A

CH3COOH + NH3 —> CH3COONH4
CH3COONH4 —> CH3CONH2 + H2O

159
Q

Better method for the formation of amides from carboxylic acids than the 2 step reaction with dilute aqueous ammonia and heating

A

Heat the acid or the ammonium salt with urea at 120 degrees

160
Q

Products when reacting a carboxylic acid and urea

A

Amide
CO2
NH3

161
Q

2 ways of forming nitriles

A
  1. From amides
  2. From halogenoalkanes
162
Q

How do you get nitriles from amides?

A

Amides can be dehydrated by heating with phosphorus (v) oxide P4O10 to give the corresponding nitrile

163
Q

How do you form nitriles from halogenoalkanes?

A

The reaction is carried out by refluxing a solution of potassium cyanide in ethanol

164
Q

Explain the produce when nitriles are formed from halogenoalkanes

A

There is an extra carbon atom in the product and the reaction can be used to ascent the homologous series - increase the length of the carbon chain

165
Q

Equation for the reaction between 1-bromopropane and KCN (in ethanol)

A

CH3CH2CH2Br + KCN —> CH3CH2CH2CN + KBr

166
Q

Reagent, conditions and product for the formation of nitriles form halogenoalkanes `

A

Reagent = potassium cyanide
Conditions = ethanol (solvent), reflux
Product = nitrile

167
Q

What’s the product of alkaline hydrolysis when the derivatives of carboxylic acids are hydrolysed?

A

The carboxylic acid

168
Q

What’s the product of acid hydrolysis when the derivatives of carboxylic acids are hydrolysed?

A

The carboxylic acid

169
Q

Explain the hydrolysis of acid chlorides to give carboxylic acids

A

Acid chlorides are hydrolysed readily by water at room temperature
The reaction may be violent and misty white fumes of HCl gas are released

170
Q

Equation for the hydrolysis of propanoyl chloride

A

CH3CH2CH2COCl + H2O —> CH3CH2COOH + HCl

171
Q

Explain the options for the hydrolysis of amides and nitriles

A

They have to be heated with alkalis or acids
The reaction with alkalis occurs more readily but the salt of the carboxylic acid is formed and acid must be added to obtain the free acid

172
Q

Which hydrolysis reaction of amides and nitriles occurs more readily but what is the issue with it?

A

The reaction with alkalis occurs more readily but the salt of the carboxylic acid is formed and acid must be added to obtain the free acid

173
Q

What are used as reagents for the hydrolysis of amides and nitriles and why?

A

Sodium hydroxide or hydrochloride acid
The reaction is very slow with water

174
Q

Explain the base catalysed reaction for the hydrolysis of modes and nitriles

A

The salt is formed with amides and nitriles. The mixture is refluxed. Ammonia gas, which turns red litmus blue, is given off with both reagents. HCl is added to generate the free acid.

175
Q

How can we identify ammonia gas?

A

Turns red litmus blue

176
Q

Equation for the hydrolysis of ethanamide or ethane nitrile to a carboxylic acid

A

CH3CONH2 or CH3CN ——> CH3COONa + NH3 ——> CH3COOH
NaOH. HCl

177
Q

Explain the acid catalysed reaction for the hydrolysis of amides and nitriles to carboxylic acids

A

Acid is formed with amides and nitriles. The mixture is refluxed.

178
Q

Equation for the acid catalysed hydrolysis of ethanamide or ethaneitrile

A

CH3CONH2 or CH3CN ——> CH3COOH + NH4Cl
HCl

179
Q

How are esters hydrolysed by water?

A

Very slowly

180
Q

Conditions for the hydrolysis of esters

A

Base catalysed or acid catalysed
The reagents are refluxed

181
Q

General equation for the hydrolysis of esters

A

ester + water —><— carboxylic acid + alcohol

182
Q

Equation for the hydrolysis of ethyl ethanoate

A

CH3COOCH2CH3 + H2O —><— CH3COOH + CH3CH2OH

183
Q

Which reaction is the reverse of esterification?

A

The hydrolysis of esters

184
Q

What is the product of the hydrolysis of esters when the reaction is base catalysed using aqueous sodium hydroxide solution?

A

The salt of the carboxylic acid - CH3COONa

185
Q

Explain base catalysed hydrolysis of ester reactions

A

The alkali forces the position of equilibrium to move to the right by removing the acid, which if formed by reaction with it to form the salt

186
Q

Are the hydrolysis of esters reactions normally base or acid catalysed? Why?

A

Base catalysed
The alkali forces the position of equilibrium to move to the right by removing the acid, which is formed by reacting with it to form the salt
In this way, the reaction can go to completion and this is why the reaction is normally based on catalysed

187
Q

Which reaction is more efficient for the hydrolysis of esters - base or acid catalysed?

A

Base catalysed

188
Q

Which cause more damage when spilt on clothes made from polyesters - acids or alkalis? Why?

A

Allkalis
In the hydrolysis of esters, alkali forces the position of equilibrium to move to the right by removing the acid, which is formed by reacting with it to form the salt

189
Q

What is used during the reduction of nitriles?

A

Lithium tetrahydridoaluminate (III) - LIAlH4

190
Q

What are nitriles reduced to?

A

Primary amines

191
Q

What do primary amines form from the reduction of?

A

Nitriles

192
Q

Conditions for the reduction of nitriles

A

The reagents are refluxed in ether (ethoxyethane) under anhydrous conditions

193
Q

Equation for the reduction of ethanenitrile

A

CH3CH + 4[H] —> CH3CH2NH2

194
Q

CH3Ch2NH2

A

Aminoethane/ethylamine

195
Q

Possible reagents for the reduction of nitriles

A

LiAlH4
Hydrogen and nickel catalyst
Sodium metal/ethanol

196
Q

Preferred reagent for the reduction of nitriles + why

A

LiAlH4
Yields are higher

197
Q

What happens when you reduce nitriles with sodium/ethanol as a reagent?

A

It produced a secondary amine as a byproduct

198
Q

Equation for the reduction of ethanenitrile with sodium/ethanol as a reagent

A

CH3CH2CN —> CH3Ch2Ch2NH2 + (CH3CH2CH2)2NH

199
Q

Explain the positive character of the carbon in ethanoyl chloride

A

The presence of two highly electronegative atoms, oxygen and chlorine, bonded to a carbon atom increases the positive character of the carbon considerably

200
Q

Which element has a positive character in ethanoyl chloride?

A

Carbon

201
Q

What does ethanoyl chloride react readily with?

A

Water
Alcohols
Phenol
Primary amines
Ammonia

202
Q

What reacts readily with all of the following?
Water
Alcohols
Phenol
Primary amines
Ammonia

A

Ethanoyl chloride

203
Q

What does ethanoyl chloride form with water?

A

Carboxylic acid

204
Q

What does ethanoyl chloride form with alcohols?

A

Ester

205
Q

What does ethanoyl chloride form with phenol?

A

Ester

206
Q

What does ethanoyl chloride form with primary amines?

A

N-substituted amide

207
Q

what does ethanoyl chloride form with ammonia?

A

Amide

208
Q

What happens in all of the reactions of ethanol chloride?

A

HCl is eliminated from the product

209
Q

Conditions for all of the reactions of ethanoyl chloride

A

Room temperature
Anhydrous conditions

210
Q

Equation for the reaction of ethanoyl chloride and propanoic acid

A

CH3COCl + CH3Ch2CH2OH —> CH3COOCH2CH2CH3 + HCl

211
Q

What is terylene?

A

Polyester

212
Q

other name for polyester?

A

Terylene

213
Q

What type of reaction is terylene made in?

A

A condensation reaction

214
Q

Explain the condensation reaction of terylene

A

Condensation reaction i.e - by the reaction of two bifunctional molecules to form the polymer with the elimination of water

215
Q

What is terylene mainly used as?

A

A synthetic fibre

216
Q

What are the 2 compounds which are reacted to form terylene?

A

Benzene- 1,4 - dicarboyxlic acid (terephthalic acid)
Ethane- 1,2 - diol (ethylene glycol)

217
Q

What can we represent teryene as?

A

A repeat unit

218
Q

What, basically, are the two things that we react to form terylene?

A

An acid and an alcohol

219
Q

Why is soda lime (used in the reduction of decarboxylation of carboxylic acids) called this?

A

Soda —> NaOH
Lime —> Ca(OH)2

Soda-lime —> [Ca(OH)2/NaOH]

220
Q

Why is the alkane formed one less carbon than the carboxylic acid during decarboxylation?

A

Since CO2 is removed

221
Q

What do we do when asked to explain acid chloride formation?

A

Choose any of the following reagents:
-PCl4
-PCl5
-SOCl2

222
Q

CH3CONH2

A

Ethanamide

223
Q

Ethanamide

A

CH3CONH2

224
Q

Why is heating the acid or its ammonium salt with urea at 120 degrees the better method for the formation of amides?

A

Since the produce are gases, making them easy to separate as they naturally escape

225
Q

What is the preferred method for the formation of acid chlorides and why?

A

Using SOCl2 as a reagent
The by-products are easier to separate (SO2 and HCl are gases)

226
Q

How are carboxylic acids produced from acid chlorides?

A

By hydrolysing them at room temperature

227
Q

What’s more important when we consider boiling points - chain length or bonding?

A

Bonding

228
Q

Arrange the following in order of increasing boiling point
Propan-1-ol, butane, ethanoic acid, propanal, propane

A

Propane<butane<propanal<propan-1-ol<ethanoic acid

229
Q

Why does butane have a higher boiling point than propane?

A

Longer chain alkane = more van der Waal forces

230
Q

What has the highest boiling point - butane or propanal, and why?

A

Propanal
Permanent dipole = forms dipole forces

231
Q

What has the highest boiling point - propan-1-ol or propanal, and why?

A

Propan-1-ol forms hydorgen bonds, Propanal doesn’t

232
Q

Can aldehydes and ketones form hydrogen bonds?

A

Not with themselves, only with water

233
Q

What has the highest boiling point - propan-1-ol or ethanoic acid, and why?

A

Ethanoic acid
Forms 2 hydrogen bonds

234
Q

Catalyst for the base catalysed hydrolysis reaction of amides and nitriles

A

NaOH

235
Q

Issue with HCl gas

A

Toxic

236
Q

How do alkalis cause more damage than acid when spilled on clothes made from polyesters?

A

It hydrolyses the fibres

237
Q

How many ways of naming amines are there?

A

2

238
Q

Type of HCl specifically used to generate a free acid when forming a carboxylic acid from a nitrile

A

aq

239
Q

How do we convert between moldm^-3 and gdm^-3?

A

Moldm-3 to gdm-3
xMr

gdm-3 to moldm-3
Divide by Mr

240
Q

How would the hydrolysis of esters be base catalysed?

A

With NaOH

241
Q

How would the hydrolysis of esters be acid catalysed?

A

With HCl

242
Q

How could CH3COONa be represented in the base catalysed reaction of the hydrolysis of amides and nitriles?

A

CH3COO-

243
Q

Aromatic carboxylic acid

A

Wheee the -COOH group is directly attached to the benzene ring

244
Q

How do we go from CH3COOH to CH2ClCOOH?

A

Cl2
Room temperature + UV

245
Q

What do we show when something undergoes hydrolysis with NaOH?

A

The O-Na+

eg: CH3CH2COO-Na+

246
Q

How does an aromatic carboxylic acid salt appear and how does the final acid appear? Why?

A

Salt - colourless solution
Acid - white precipitate (insoluble in water)

247
Q

Why can’t we use NaOH to remove the HCl when reacting phenol and CH3COCl?

A

The CH3COCl would react preferably with the NaOH

248
Q

What happens when you react an amide and NaOH?

A

Na+O- from NH2

249
Q

Which is a weaker acid - phenol or carboxylic acid? Explain

A

Phenols are weaker acids than carboxylic acids since the delocalisation of the negative charge is less in the phenoxide ion than the carboxylate ion

250
Q

What do we show when showing the hydrolysis reaction of an ester and why?

A

Show it reacting with NaOH since its base catalysed (don’t just show it reacting with water)

A level Chemistry (39 decks)

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