DP Chemistry (last assessment 2024)
Question 18M.2.hl.TZ2.e
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.hl.TZ2.e |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Explain | Question number | e | Adapted from | N/A |
e.
[Maximum mark: 2]
18M.2.hl.TZ2.e
Some physical properties of molecular substances result from the different types of forces between their molecules.
Carbon and silicon are elements in group 14.
Explain why CO2 is a gas but SiO2 is a solid at room temperature.
[2]
Markscheme
CO2 «non-polar» «weak» London/dispersion forces/instantaneous induced dipole-induced dipole forces between molecules
SiO2 network/lattice/3D/giant «covalent» structure
M1: The concept of “between” is essential.
[2 marks]
