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Date May 2017 Marks available 1 Reference code 17M.3.hl.TZ2.3
Level HL Paper 3 Time zone TZ2
Command term Estimate Question number 3 Adapted from N/A

Question

Polymer nanocomposites often have better structural performance than conventional materials. Lithographic etching and metal coordination are two methods of assembling these nanocomposites.

Dendrimers are highly branched nanoparticles with a wide range of usage. One such dendrimer is PAMAM, or polyamidoamine.

The first step in the synthesis is to make the core by reacting ethane-1,2-diamine with methylpropenoate.

Estimate the atom economy of this first step.

[1]
c.

Suggest, giving one reason, whether this is an addition or condensation reaction.

[1]
c.ii.

Subsequent steps proceed under differing conditions, forming the dendrimer polymer with the following repeating unit.

State the name of one functional group in this repeating unit.

[1]
c.iii.

Markscheme

100%

 

Accept “almost 100%” if a catalyst is referred to.

[1 mark]

c.

addition AND no atoms removed/all atoms accounted for/no loss of water/ammonia/inorganic by-product/small molecules
OR
addition AND there is only one «reaction» product

[1 mark]

c.ii.

amido
OR
amino

 

Accept “amide/carboxamide/carbamoyl” for “amido”.

Accept “amine“ for “amino”.

Accept “carbonyl”.

[1 mark]

c.iii.

Examiners report

[N/A]
c.
[N/A]
c.ii.
[N/A]
c.iii.

Syllabus sections

Options » A: Materials » A.5 Polymers
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