DP Chemistry (last assessment 2024)
Question 21M.2.hl.TZ2.d
| Date | May 2021 | Marks available | [Maximum mark: 3] | Reference code | 21M.2.hl.TZ2.d |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Justify, Suggest | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 3]
21M.2.hl.TZ2.d
The properties of elements can be predicted from their position in the periodic table.
Suggest, giving reasons, the relative volatilities of SCl2 and H2O.
[3]
Markscheme
H2O forms hydrogen bonding «while SCl2 does not» ✓
SCl2 «much» stronger London/dispersion/«instantaneous» induced dipole-induced dipole forces ✓
Alternative 1:
H2O less volatile AND hydrogen bonding stronger «than dipole–dipole and dispersion forces» ✓
Alternative 2:
SCl2 less volatile AND effect of dispersion forces «could be» greater than hydrogen bonding ✓
Ignore reference to Van der Waals.
Accept “SCl2 has «much» larger molar mass/electron density” for M2.
