6.1.3: Carboxylic acids and esters Flashcards

1
Q

What is the functional group of a carboxylic acid?

A

-COOH (C=O and C-OH)

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2
Q

How do you name carboxylic acids?

A

-oic acid

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3
Q

Are carboxylic acids soluble in water? Why? What

influences their solubility

A

Yes. Acid group can form hydrogen bonds with water molecules

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4
Q

What are the intermolecular forces in carboxylic

acids?

A

Hydrogen bonds in solid state - very strong.

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5
Q

What are esters (what are they formed from)?

Functional group, general formula?

A

Formed from carboxylic acids and alcohols.

RCOOR’ (C=O, C-O-C)

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6
Q

Write an equation for the reaction of ethanoic acid with propan-1-ol

A

CH3COOH + CH3CH2CH2OH → CH3COOCH2CH2CH3 + H2O

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7
Q

How do you name esters?

A

Start with the alcohol group that has replaced the hydrogen, then acid part e.g. propyl (from alcohol) ethanoate (from carboxylic acid)

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8
Q

What characteristic physical properties do esters

have?

A

Volatile, pleasant fruity smells e.g. apple, pear

drops

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9
Q

What are some uses of esters?

A

Flavourings, perfumes (both for longer chains), solvents (short chains), plasticisers

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10
Q

How could you distinguish carboxylic acids from other -OH containing compounds?

A

Add NaHCO3, acids will produce sodium salt, water and carbon dioxide.

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11
Q

Write an equation for the reaction of ethanoic acid

with NaOH.

A

CH3COOH + NaOH → H2O + CH3COO-Na+

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12
Q

Write an equation for the reaction of ethanoic acid

with Na2CO3

A

2CH3COOH + Na2CO3 → 2CH3COO-Na+ + H2O + CO2

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13
Q

Write an equation for the reaction of ethanoic acid with

calcium oxide

A

2CH3COOH + CaO → (CH3COO)2Ca + H2O

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14
Q

What catalyst is needed for the formation of esters

from alcohols and carboxylic acids?

A

Concentrated strong acid e.g. H2SO4

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15
Q

What catalyst is needed for the hydrolysis of esters?

A

Dilute strong acid e.g. H2SO4

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16
Q

What is an alternative method of hydrolysis?

A

Base hydrolysis

17
Q

What are the advantages of base hydrolysis?

A

Reaction goes to completion due to neutralisation
by base - more product in the mixture than acid
catalysed hydrolysis.

18
Q

What are carboxylic acid derivatives?

A

Molecules that have the acyl group as part of their structure, formed from carboxylic acids

19
Q

Name two acid derivatives and give their functional

groups.

A

Acyl chlorides: RCOCl

Acid anhydrides: RCOOCR / (RCO)2O

20
Q

How do you form an acyl chloride?

A

React a carboxylic acids with SOCl2

21
Q

If the nucleophile is ammonia for the acylation of acyl
chlorides or acid anhydrides, what are the products
of the reaction?

A

an amide

22
Q

Write an equation for the reaction of ethanoyl

chloride and ammonia

A

CH3COCl + 2NH3 → CH3CONH2 + NH4Cl

23
Q

If the nucleophile is a primary amine, what are the
products of the acylation of acyl chlorides or acid
anhydrides?

A

N-substituted amide

24
Q

Write an equation for the reaction of ethanoyl

chloride and methylamine

A

CH3COCl + CH3NH2 → CH3CONHCH3 + CH3NH3Cl

25
Q

If the nucleophile is an alcohol, what are the
products of the acylation of acyl chlorides or acid
anhydrides?

A

an ester

26
Q

Write an equation for the reaction of ethanoyl

chloride and ethanol

A

CH3COCl + CH3CH2OH → CH3COOCH2CH3 + HCl

27
Q

If the nucleophile is water, what are the products of

the acylation of acyl chlorides or acid anhydrides?

A

Carboxylic acid (hydrolysis produces an ester linkage)

28
Q

What is the name of this reaction (the acylation of acyl chlorides/acid anhydrides with water as a nucleophile)?

A

hydrolysis

29
Q

Write an equation for the reaction of ethanoyl

chloride and water.

A

CH3COCl + H2O → CH3COOH + HCl