DP Chemistry (last assessment 2024)
Question 19M.3.sl.TZ2.8
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.3.sl.TZ2.8 |
| Level | sl | Paper | 3 | Time zone | TZ2 |
| Command term | Sketch, State | Question number | 8 | Adapted from | N/A |
8.
[Maximum mark: 3]
19M.3.sl.TZ2.8
Sucrose is a disaccharide.
(a)
State the name of the functional group forming part of the ring structure of each monosaccharide unit.
[1]
Markscheme
acetal
OR
ether [✔]
Note: Accept “glycosidic bond/linkage” but not “glucosidic”.
Do not accept “hemiacetal”.
Examiners report
This was reasonably answered although there were some students who responded with ester or hemiacetal which is incorrect.
(b)
Sketch the cyclic structures of the two monosaccharides which combine to form sucrose.
[2]
Markscheme
[✔]
[✔]
Examiners report
This question was very poorly answered. Many students lost marks due to sloppy drawing and incorrect bond linkages. Some students did not separate the two saccharides as instructed.
