DP Chemistry (last assessment 2024)
Question 19M.3.hl.TZ2.5c
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.hl.TZ2.5c |
| Level | hl | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 2]
19M.3.hl.TZ2.5c
Polymers have a wide variety of uses but their disposal can be problematic.
(c)
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 [✔]
Note: Accept “lowers density/melting point”.
Examiners report
This was a well-answered question; with most candidates identifying at least one method plasticizers affect the properties of plastic.
