DP Chemistry (last assessment 2024)
Question 17N.3.sl.TZ0.b.i
| Date | November 2017 | Marks available | [Maximum mark: 2] | Reference code | 17N.3.sl.TZ0.b.i |
| Level | sl | Paper | 3 | Time zone | TZ0 |
| Command term | Describe | Question number | b.i | Adapted from | N/A |
b.i.
[Maximum mark: 2]
17N.3.sl.TZ0.b.i
The development of materials with unique properties is critical to advances in industry.
Low density polyethene (LDPE) and high density polyethene (HDPE) are both addition polymers.
Describe how the structures of LDPE and HDPE affect one mechanical property of the plastics.
[2]
Markscheme
branching in LDPE prevents close packing «of chains»
LDPE is more flexible/less rigid
OR
LDPE has lower «tensile» strength
Do not accept “difference in density”.
Award [1 max] for stating “branching in LDPE AND little/no branching in HDPE”.
