Question 20N.3.sl.TZ0.a
| Date | November 2020 | Marks available | [Maximum mark: 1] | Reference code | 20N.3.sl.TZ0.a |
| Level | sl | Paper | 3 | Time zone | TZ0 |
| Command term | Suggest | Question number | a | Adapted from | N/A |
In order to determine the oil content of different types of potato crisps (chips), a student weighed of crushed crisps and mixed them with of non-polar solvent.
She assumed all the oil in the crisps dissolved in the solvent.
The student then filtered the mixture to remove any solids, and gently heated the solution on a hot plate to evaporate the solvent.
She measured the mass of the oil that remained from each type of crisps
Suggest why a non-polar solvent was needed.
[1]
oil is non-polar «and dissolves best in non-polar solvents»
OR
oil does not dissolve in polar solvents ✔
Do not accept “like dissolves like” only.
A well answered question where replies used all the alternatives provided. Very few candidates limited their answer to "like dissolves like" and while this expression was used most student elaborated with higher quality answer. Some common incorrect responses included students talking about dissolving the crisps (chips) or indicating the oil was a polar compound.
