| Date | May 2013 | Marks available | 2 | Reference code | 13M.3.sl.TZ1.B3 |
| Level | SL | Paper | 3 | Time zone | TZ1 |
| Command term | Deduce | Question number | B3 | Adapted from | N/A |
Question
The structures of retinol (vitamin A) and vitamin D are given in Table 21 of the Data Booklet. Deduce whether each vitamin is water-soluble or fat-soluble and explain your answer by referring to their structures.
Markscheme
both fat soluble;
both contain mainly non-polar/hydrocarbon parts (and only one OH group) / OWTTE;
Do not award ECF if water soluble is stated for either vitamin.
Do not award M2 for answers such as “since both do not have many OH groups present”.
Examiners report
The majority of candidates identified the solubility of both vitamins correctly in part (a). The explanation was correctly scored by only half of the candidates, while the rest talked about the OH group and did not discuss the main part of the molecule.
