Degradable Polymers — Structured Questions (Cambridge International A-Level Chemistry): Exam Questions

State what is meant by the term hydrolysis.

State the reagents and conditions required for the acid hydrolysis of a polyamide.

Fig. 1.1 shows a section of a polyamide.

Fig. 1.1

Draw the skeletal formulae of the organic products formed when the polyamide is treated with dilute acid and heated under reflux.

Extract:

Fig. 1.1 shows a section of a polyamide.

{align=center} Fig. 1.1

Draw the skeletal formulae of the organic products formed when the polyamide in Fig. 1.1 is treated with excess aqueous sodium hydroxide and heated under reflux.

Fig. 1.1 shows a section of a nylon polymer.

Fig. 1.1

i) Draw the skeletal formulae of the two monomers that could be used to make this nylon.

ii) State the type of polymerisation involved in the formation of this nylon.

Extract:

Fig. 1.1 shows a section of a nylon polymer.

Explain why clothing made from nylon is easily damaged by spillages of strong acids or strong alkalis.

Extract:

Fig. 1.1 shows a section of a nylon polymer.

Fig. 1.2 shows the structure of Nomex, an aromatic polyamide.

Fig. 1.2

Explain why Nomex has a higher melting point than nylon.

Extract:

Fig. 1.2 shows the structure of Nomex, an aromatic polyamide.

i) Draw the skeletal formulae of the two monomers used to manufacture Nomex.

ii) State the formula of the by-product formed during this polymerisation reaction.

i) Name an example of a synthetic polyester and a synthetic polyamide.

ii) Polyesters and polyamides are formed by condensation reactions.

Name a molecule which is commonly eliminated in such reactions.

Table 2.1 shows the repeat units of a number of polymers. Place a tick (✓) against the ones which are biodegradable.

Table 2.1

Extract:

Table 2.1 shows the repeat units of a number of polymers. Place a tick (✓) against the ones which are biodegradable.

Table 2.1

Draw the structural formulae of the two monomers used to form polymer B.

Table 1.1 shows the structural formulae of three amino acids.

Table 1.1

State which of the amino acids, T, U or V, has the highest pH in an aqueous solution, and explain your answer.

amino acid ......................................................

explanation ......................................................

State how many different dipeptides could be formed from a reaction mixture consisting of amino acids T and U.

Despite containing a high proportion of carbon and hydrogen atoms, many polypeptides are soluble in water. Explain why. In your answer, you should refer to the functional groups present in a polypeptide chain.