DP Chemistry (first assessment 2025)
Question 20N.2.HL.TZ0.a
| Date | November 2020 | Marks available | [Maximum mark: 2] | Reference code | 20N.2.HL.TZ0.a |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Deduce | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
20N.2.HL.TZ0.a
Deduce the products of the hydrolysis of a non-substituted phospholipid, where and represent long alkyl chains.
[2]
Markscheme
glycerol ✔
both fatty acids AND phosphoric acid ✔
Accept either names OR structures.
Accept “long chain carboxylic acid” for “fatty acid”.
Penalize once only if an incorrect name is given for a correct structure or vice-versa.
Examiners report
Not as well answered as expected. However, many candidates managed to score at least one point. Quite a few lost the only mark due to wrong linkage. Some students drew fatty acid structures with aldehydes or phosphoric acid with incorrect bond linkages in the structure (OH-).
Syllabus sections
Structure 2. Models of bonding and structure » Structure 2.4—From models to materials » Structure 2.4.6—Condensation polymers form by the reaction between functional groups in each monomer with the release of a small molecule. Represent the repeating unit of polyamides and polyesters from given monomer structures.