Polymers And Life

Question 1

Acid Hydrolysis of Esters

Answer 1

ROOR’ + H2O ROOH + OHR’
Ester + Water Carboxylic Acid + Alcohol
Reflux ester with excess water and dilute acid catalyst (sulfuric)
Reversible

Question 2

Alkali Hydrolysis of Esters

Answer 2

Ester + Alkali/base —> Carboxylate salt + alcohol
Reflux with dilute Alkali
Non reversible and goes to completion
preferred

Question 3

Acid Hydrolysis of Amides

Answer 3

1° amide + Water —> Carboxylic Acid + ammonium salt
- forms ammonia —-> ammonium with acid
2° amide + water —> Carboxylic Acid + 1°amine salt
Heat with mod conc. sulfuric or hydrochloric acid
CN bond broken

Question 4

Alkaline Hydrolysis of Amides

Answer 4

1° amide + Alkali —-> Carboxylate ion + ammonia gas
2° amide + Alkali —> Carboxylate ion + amine
Heated with mod conc. Alkali (normally NaOH)

Question 5

Differences between addition and condensation polymerisation

Answer 5

Reaction- addition reaction vs condensation reaction (form amide or ester link)
Monomer- addition tends to be unsaturated, condensation need two functional groups
Reactivity- addition has unreactive polymer chain, condensation has links that can be hydrolysed

Question 6

Acidic nature of Carboxylic acids

Answer 6

Weak acids. Partially dissociate into Carboxylate ions and H+ ions in water (position of equilibrium to left)
Carboxylic acid + metal —> salt + hydrogen
– heat under reflux
Carboxylic acid + carbonate —> salt + CO2 + H2O
– fizzes