DP Chemistry (last assessment 2024)
Question 19M.2.hl.TZ2.a
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.hl.TZ2.a |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Explain | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
19M.2.hl.TZ2.a
The thermal decomposition of dinitrogen monoxide occurs according to the equation:
2N2O (g) → 2N2 (g) + O2 (g)
The reaction can be followed by measuring the change in total pressure, at constant temperature, with time.
The x-axis and y-axis are shown with arbitrary units.
Explain why, as the reaction proceeds, the pressure increases by the amount shown.
[2]
Markscheme
increase in the amount/number of moles/molecules «of gas» [✔]
from 2 to 3/by 50 % [✔]
Examiners report
Students were able in general to relate more moles of gas to increase in pressure.
