DP Chemistry (last assessment 2024)
Question 19M.2.hl.TZ2.2e
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.2.hl.TZ2.2e |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Outline | Question number | e | Adapted from | N/A |
e.
[Maximum mark: 1]
19M.2.hl.TZ2.2e
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.
(e)
The experiment gave an error in the rate because the pressure gauge was inaccurate.
Outline whether repeating the experiment, using the same apparatus, and averaging the results would reduce the error.
[1]
Markscheme
no AND it is a systematic error/not a random error
OR
no AND «a similar magnitude» error would occur every time [✔]
Examiners report
Almost all candidates identified the inaccurate pressure gauge as a systematic error, thus relating accuracy to this type of error.
