DP Chemistry (last assessment 2024)
Question 20N.3.hl.TZ0.4c(iii)
| Date | November 2020 | Marks available | [Maximum mark: 1] | Reference code | 20N.3.hl.TZ0.4c(iii) |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Suggest | Question number | c(iii) | Adapted from | N/A |
c(iii).
[Maximum mark: 1]
20N.3.hl.TZ0.4c(iii)
There has been significant growth in the use of carbon nanotubes, CNT.
(c(iii))
Suggest a gas which should be continuously passed over the molten magnesium in the electrolytic cell.
[1]
Markscheme
argon//helium/ ✔
Accept any identified noble/inert gas.
Accept name OR formula.
Do not accept “nitrogen/“.
Examiners report
The most common error here was "nitrogen" as the gas that should be continuously passed over the molten magnesium in the electrolytic cell. Magnesium can react with nitrogen forming magnesium nitride, which makes this choice of gas unsuitable (unlike argon for example).
