Topic 3.9 - Carboxylic Acids and Derivatives

What is a carboxylic acid?

Functional group?

-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

CH 3 COOH + CH 3 CH 2 CH 2 OH → CH 3 COOCH 2 CH 2 CH 3 + H 2 O

How do you name esters?

Start with the 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.

What are some common

natural esters?

Fats and oils

In what way is the

carboxylic acid group

polarised? (Diagram)

Write an equation for the

equilibrium formed by a

ethanoic acid in solution

CH 3

COOH (aq) ⇌ CH 3

COO - (aq) + H + (aq)

What happens to the

negative charge on the

ethanoate ion in terms of

electrons?

Electrons delocalise so the negative charge is

shared across the whole of the carboxylate group

How could you distinguish

carboxylic acids from other

-OH containing

compounds?

Add NaHCO 3 , acids will produce sodium

salt, water and carbon dioxide.

Write an equation for the

reaction of ethanoic acid

with NaOH

CH 3

COOH + NaOH → H 2

O + CH 3

COO -

Na +

Write an equation for the

reaction of ethanoic acid

with Na 2 CO 3 .

2CH 3 COOH + Na 2 CO 3 → 2CH 3 COO -

Na + + H 2 O + CO2

What catalyst is needed for

the formation of esters from

alcohols and carboxylic

acids?

Concentrated strong acid e.g. H 2 SO 4

What catalyst is needed for

the hydrolysis of esters?

Dilute strong acid e.g. H 2 SO 4

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.

Which alcohol forms the

esters that make up animal

and vegetable oils?

Glycerol / propane-1,2,3-triol

What is the difference

between oil and fat?

Oils are liquid at room temperature, fats are

solids; fats are usually saturated, oils are not

What are the products of

hydrolysing fats and oils?

Propane-1,2,3-triol and sodium salts of the acids

that make up the ester (hydrolysed with NaOH)

What are the uses of these

products

(Propane-1,2,3-triol and

sodium salts)?

Soaps and cleaning products