6.1.3 - Carboxylic Acids and Esters Flashcards
What is the functional group
of a carboxylic acid?
-COOH (C=O and C-OH)
How do you name
carboxylic acids?
-oic acid
Are carboxylic acids soluble
in water? Why? What
influences their solubility.
Yes. Acid group can form hydrogen bonds with
water molecules
What are the intermolecular
forces in carboxylic acids?
Hydrogen bonds in solid state - very strong.
What are esters (what are they
formed from)? Functional
group, general formula?
Formed from carboxylic acids and alcohols.
RCOOR’ (C=O, C-O-C)
Write an equation for the
reaction of ethanoic acid
with propan-1-ol
CH₃COOH + CH₃CH₂CH₂OH → CH₃COOCH₂CH₂CH₃ + H₂O
How do you name esters?
Start with the alcohol group that has replaced the
hydrogen, then acid part e.g. propyl (from
alcohol) ethanoate (from carboxylic acid).
What characteristic physical
properties do esters have?
Volatile, pleasant fruity smells e.g. apple, pear
drops
What are some uses of
esters?
Flavourings, perfumes (both for longer chains),
solvents (short chains), plasticisers.
How could you distinguish
carboxylic acids from other
-OH containing
compounds?
Add NaHCO₃
acids will produce sodium
salt, water and carbon dioxide.
Write an equation for the
reaction of ethanoic acid
with NaOH
CH₃COOH + NaOH → H₂O + CH₃COO-Na+
Write an equation for the
reaction of ethanoic acid
with Na₂CO₃
.
2CH₃COOH + Na₂CO₃ → 2CH₃COO-Na+ + H₂O + CO₂
Write an equation for the reaction of
ethanoic acid with calcium oxide
2CH₃COOH + CaO → (CH₃COO)₂Ca + H₂O
What catalyst is needed for
the formation of esters from
alcohols and carboxylic
acids?
Concentrated strong acid e.g. H₂SO₄
What catalyst is needed for
the hydrolysis of esters?
Dilute strong acid e.g. H₂SO₄
What is an alternative
method of hydrolysis?
Base hydrolysis
What are the advantages of
base hydrolysis?
Reaction goes to completion due to neutralisation
by base - more product in the mixture than acid
catalysed hydrolysis.
What are carboxylic acid
derivatives?
Molecules that have the acyl group as part of
their structure, formed from carboxylic acids
Name two acid derivatives
and give their functional
groups
Acyl chlorides: RCOCl
Acid anhydrides: RCOOCR / (RCO)2O
How do you form an acyl
chloride?
React a carboxylic acids with SOCl₂
If the nucleophile is
ammonia for the acylation of
acyl chlorides or acid
anhydrides, what are the
products of the reaction?
An amide
Write an equation for the
reaction of ethanoyl chloride
and ammonia.
CH₃COCl + 2NH₃ → CH₃CONH₂ + NH₄Cl
Write an equation for the
reaction of ethanoyl chloride
and ammonia.
CH3COCl + 2NH3
→ CH3CONH2
+
NH4Cl
If the nucleophile is a
primary amine, what are the
products of the acylation of
acyl chlorides or acid
anhydrides?
N-substituted amide
Write an equation for the
reaction of ethanoyl chloride
and methylamine
CH₃COCl + CH₃NH₂ → CH₃CONHCH₃ + CH₃NH₃Cl
If the nucleophile is an
alcohol, what are the
products of the acylation of
acyl chlorides or acid
anhydrides?
An ester
Write an equation for the
reaction of ethanoyl chloride
and ethanol.
CH₃COCl + CH₃CH₂OH → CH₃COOCH₂CH₃ + HCl
If the nucleophile is water,
what are the products of the
acylation of acyl chlorides or
acid anhydrides?
Carboxylic acid (hydrolysis produces an
ester linkage)
What is the name of this
reaction (the acylation of
acyl chlorides/acid
anhydrides with water as a
nucleophile)?
hydrolysis
Write an equation for the
reaction of ethanoyl chloride
and water..
CH₃COCl + H₂O → CH₃COOH + HCl
