DP Chemistry (last assessment 2024)
Question 18M.3.sl.TZ2.17
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.sl.TZ2.17 |
| Level | sl | Paper | 3 | Time zone | TZ2 |
| Command term | Explain | Question number | 17 | Adapted from | N/A |
17.
[Maximum mark: 2]
18M.3.sl.TZ2.17
Morphine and diamorphine (heroin) are both opioids.
Explain why diamorphine is more potent than morphine using section 37 of the data booklet.
[2]
Markscheme
morphine has hydroxyl/OH groups/is more polar AND diamorphine has ester/ethanoate/acetate groups/is less polar/is lipid soluble
crossing blood brain barrier is easier for non-polar/less polar compounds/for lipid soluble compounds
Accept “alcohol/hydroxy” for “hydroxyl” but not “hydroxide”.
Accept "fats" for "lipid".
[2 marks]
