DP Chemistry (last assessment 2024)
Question 19M.2.hl.TZ1.3c
Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.hl.TZ1.3c |
Level | hl | Paper | 2 | Time zone | TZ1 |
Command term | Describe | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 2]
19M.2.hl.TZ1.3c
This question is about sodium and its compounds.
(c)
Describe the structure and bonding in solid sodium oxide.
[2]
Markscheme
«3-D/giant» regularly repeating arrangement «of ions»
OR
lattice «of ions» [✔]
electrostatic attraction between oppositely charged ions
OR
electrostatic attraction between Na+ and O2− ions [✔]
Note: Do not accept “ionic” without description.
Examiners report
Many candidates lost one or two marks for missing “electrostatic forces” between “oppositely charged ions”, or “lattice”. Some candidates’ answers referred to covalent bonds and shapes of molecules.
