DP Chemistry (last assessment 2024)

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Question 20N.3.hl.TZ0.b(iii)

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Date November 2020 Marks available [Maximum mark: 2] Reference code 20N.3.hl.TZ0.b(iii)
Level hl Paper 3 Time zone TZ0
Command term Explain Question number b(iii) Adapted from N/A
b(iii).
[Maximum mark: 2]
20N.3.hl.TZ0.b(iii)
Carbon fibre reinforced plastic (CFRP) is a useful composite. Epoxy is a thermoset polymer that is used as a binding polymer when making CFRP.

 

Explain why phthalates are replaced by other plasticizers in the production of plastics.

[2]

Markscheme

Any two of:
readily released into environment
OR
have weak intermolecular forces «rather than covalent bonds between chains» ✔

get into biological systems by ingestion/inhalation ✔

interrupt endocrine systems
OR
affect release of hormones
OR
effect development of male reproductive system ✔

considered carcinogenic
OR
can cause cellular damage ✔

can cause early puberty in females ✔

can cause thyroid effects ✔

can cause asthma ✔


Do not accept just “are a health concern”.

Examiners report

This question required an explanation of why phthalates are replaced by other plasticizers in the production of plastics. This question was found to be very challenging and even the better candidates failed to score both marks. The weaker candidates typically stated that they are just a health concern, which was deemed insufficient to warrant even a salvage mark.