DP Chemistry (first assessment 2025)
Question 19M.2.SL.TZ2.7d
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.SL.TZ2.7d |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Suggest | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 1]
19M.2.SL.TZ2.7d
(d)
Lecithin aids the body’s absorption of vitamin E.
Suggest why vitamin E is fat-soluble.
[1]
Markscheme
long non-polar/hydrocarbon chain «and only one hydroxyl group»
OR
forms London/dispersion/van der Waals/vdW interactions with fat [✔]
Note: Accept “alcohol/hydroxy/OH” for “hydroxyl” but not “hydroxide”.
Examiners report
This question was also not answered well even though it has appeared on previous tests. Many students missed the idea of a long or large non-polar chain when describing the structure.
Syllabus sections
Structure 2. Models of bonding and structure » Structure 2.2—The covalent model » Structure 2.2.9—Given comparable molar mass, the relative strengths of intermolecular forces are generally: London (dispersion) forces < dipole–dipole forces < hydrogen bonding. Explain the physical properties of covalent substances to include volatility, electrical conductivity and solubility in terms of their structure.