Question 23M.3.SL.TZ2.21
| Date | May 2023 | Marks available | [Maximum mark: 2] | Reference code | 23M.3.SL.TZ2.21 |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | State, Suggest | Question number | 21 | Adapted from | N/A |
The production of many pharmaceutical drugs involves the use of solvents.
State one problem associated with chlorinated organic solvents as chemical waste.
[1]
Any one of:
«most are» toxic «to living organisms»
OR
incomplete combustion/incineration can produce toxic products/dioxins/phosgene
OR
carcinogenic ✓
«some can be» greenhouse gases ✓
ozone-depleting ✓
can contribute to formation of «photochemical» smog ✓
accumulate in groundwater
OR
have limited biodegradability ✓
cost/hazards of disposal ✓
Do not accept “harmful to the environment”.
Do not accept just “pollutes water”.
Do not accept “increases acid rain/acidity/acid deposition”.
Suggest how the principles of green chemistry can be used to overcome the environmental problems caused by organic solvents.
[1]
use solvent-free synthetic methods
OR
use water/supercritical carbon dioxide/non-toxic/low-toxic/biodegradable compounds as a solvent
OR
recover/reuse solvents
OR
use a non-chlorinated solvent ✓
Accept arguments based on atom economy.
Do not accept “use solvents safer for environment” alone.