DP Chemistry (first assessment 2025)
Question 21M.2.SL.TZ1.b(ii)
| Date | May 2021 | Marks available | [Maximum mark: 1] | Reference code | 21M.2.SL.TZ1.b(ii) |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Outline | Question number | b(ii) | Adapted from | N/A |
b(ii).
[Maximum mark: 1]
21M.2.SL.TZ1.b(ii)
Outline why increasing the concentration of N2O5 increases the rate of reaction.
[1]
Markscheme
greater frequency of collisions «as concentration increases»
OR
more collisions per unit time «as concentration increases» ✔
Accept “rate/chance/probability/likelihood” instead of “frequency”.
Do not accept just “more collisions”.
Syllabus sections
Reactivity 2. How much, how fast and how far? » Reactivity 2.3—How far? The extent of chemical change » Reactivity 2.3.4—Le Châtelier’s principle enables the prediction of the qualitative effects of changes in concentration, temperature and pressure to a system at equilibrium. Apply Le Ch.telier’s principle to predict and explain responses to changes of systems at equilibrium.