PL1 - The Polyester Story

Question 1

Draw a carboxyl group

Answer 1

Question 2

How are carboxylic acids named?

Answer 2

From the parent alkane by omitting the final ‘e’ (as the suffic starts with a vowel) and adding the suffix -oic acid

Question 3

How are side chains on carboxylic acids named?

Answer 3

Counting the carbons from the carboxyl group as this is the highest priotrity group, then naming as in alkanes etc.

Question 4

How are carboxylic acids containing two carboxyl groups named?

Answer 4

With the suffic -doic acid

Question 5

Draw an example of a dicarboxylic acid

Answer 5

Question 6

What is another name for benzoic acid?

Answer 6

Benzene carboxylic acid

Question 7

What is a phenol?

Answer 7

A hydroxyl group attached to an arene ring

Question 8

What are ketones + what is their general structure?

Answer 8

Organic compounds with a carbonyl groupattached to any of the inner carbon atoms (not outer)

Have the suffix -one

Question 9

What are aldehydes and how are they named?

Answer 9

Organic compounds with a carbonyl group at the end of a carbon chain. (Hydrogen atom bonded to carbonyl group)

Have the suffic -al

Question 10

Which organic compounds are able to react with strong bases?

Which can’t?

Answer 10

Carboylic acids and phenols

Alcohols cannot

Question 11

Which organic compounds can react with carbonates and why?

How can you tell the reaction is taking place?

Answer 11

Only carboxylic acids as phenols + alcohols don’t have a high enough concentration of H⁺ ions

When they react they fizz due to the production of CO₂

Question 12

What type of reaction is the reaction between carboxylic acids and carbonates?

Answer 12

Acid-base

Question 13

Which organic compounds can react with metals and what is formed?

What type of reaction occurs?

Answer 13

Carboxylic acids, phenols, and alcohols

A salt is formed

It is a redox reaction

Question 14

What are esters and what is their general formula?

How are they named?

Answer 14

Organic compounds formed from the reaction between a carboxylic acid and an alcohol (esterification)

Named by adding -t(h)yl to the name of the alcohol followed by the name of the carboxylic acid with -oate

e.g. Butyl Propanoate, Ethyl Ethanoate

Question 15

What is often used as a catalyst during esterification and why?

Answer 15

An acid catalyst - concentrated hydrochloric or sulfuric acid

Used as the reaction is otherwise very slow

Question 16

What type of reaction is esterification?

Answer 16

A condensation reaction

Results in the elimination of a water molecule

Question 17

What is esterification specifically the result of?

Answer 17

An ester link being formed after the condenstaion reaction of the hydroxyl group in the alcohol and carboxylic acid

Question 18

What can be said about the progress of the esterification reaction?

Answer 18

It is reversible and eventually comes to equilibrium

Question 19

How can the yield of esterification be improved?

Answer 19

An excess of alcohol can be added or the water can be distilled off as it forms.

The acid catalyst also absorbs some of the water formed

This helps move the equilibrium position to the right

Question 20

What is the name of the reverse reaction of esterification?

Answer 20

Ester hydrolysis

Question 21

What are the properties/uses of esters?

Answer 21

Have strong, sweet smells that are often floral or fruity so are used in flavourings + perfumes.

Many organic compounds dissolve easily in them so they are used as solvents - e.g. in glues.

Question 22

What is the name of the ester formed from the reaction of phenol and benzoic acid?

Answer 22

Phenyl Benzoate

Question 23

When writing the formula of an ester, should the acid or alcohol part be written first?

Answer 23

Either can be written first

Question 24

What two types of reactions can be used to form polymers?

Answer 24

Addition or condensation

Question 25

What is produced from condensation polymerisation?

Answer 25

A condensation polymer and a small, stable molecule (usually H₂O or HCl)

(not strong and stable…)

Question 26

What is a polyester?

Answer 26

Condensation polymer linked by ester groups

e.g. made from a dicarboxylic acid + alcohol

Question 27

What is needed for condensation polymerisation?

Answer 27

Monomers with at least two suitable functional groups per molecule

Question 28

What is needed to make an ester from a phenol and why?

Answer 28

A more vigorous reagent to esterify it e.g. an acid anhydride

Needed as the -OH in phenol is less reactive to esterification than that in an alcohol

Question 29

What are acid anhydrides and what is the general forumla for them?

Answer 29

Organic compound made of two acyl groups bonded to the same oxygen atom

Made by remvoing 1 molecule of water from 2 carboxylic acids

Question 30

What is a diol?

Answer 30

Alcohol with two -OH groups