DP Chemistry (last assessment 2024)
Question 19N.3.hl.TZ0.5
| Date | November 2019 | Marks available | [Maximum mark: 6] | Reference code | 19N.3.hl.TZ0.5 |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Discuss, Draw, State and explain | Question number | 5 | Adapted from | N/A |
5.
[Maximum mark: 6]
19N.3.hl.TZ0.5
Kevlar® is used to make racing tires.
(a)
Draw the structure of the monomers of Kevlar® if the by-product of the condensation polymerization is hydrogen chloride.
[2]
Markscheme
OR
H2NC6H4NH2 ✔
OR
Cl(O)CC6H4C(O)Cl ✔
(b)
State and explain why plasticizers are added to polymers.
[2]
Markscheme
increases flexibility/softness/plasticity ✔
break/weaken intermolecular forces/IMF/H-bonds «between chains» ✔
(c)
Discuss why the recycling of plastics is an energy intensive process.
[2]
Markscheme
Any two of:
collection/transportation of plastic waste ✔
separation/sorting of different types «of plastic»
OR
separation/sorting of plastic from other materials ✔
melting plastic ✔
processing/washing/cleaning/drying/manufacture of recycled plastic ✔
