DP Chemistry (last assessment 2024)
Question 19M.3.sl.TZ2.5d
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.sl.TZ2.5d |
| Level | sl | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 2]
19M.3.sl.TZ2.5d
Polymers have a wide variety of uses but their disposal can be problematic.
(d)
Explain how plasticizers affect the properties of plastics.
[2]
Markscheme
Any two of:
embedded/fit between chains of polymers [✔]
prevent chains from forming crystalline regions [✔]
keep polymer strands/chains/molecules separated/apart [✔]
increase space/volume between chains [✔]
weaken intermolecular/dipole-dipole/London/dispersion/instantaneous dipoleinduced dipole/van der Waals/vdW forces «between chains» [✔]
increase flexibility/durability/softness [✔]
make polymers less brittle [✔]
Examiners report
Many students received a mark for this question although some did not because their answers were too vague.
