DP Chemistry (last assessment 2024)
Question 20N.2.hl.TZ0.4a
Date | November 2020 | Marks available | [Maximum mark: 1] | Reference code | 20N.2.hl.TZ0.4a |
Level | hl | Paper | 2 | Time zone | TZ0 |
Command term | Outline | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 1]
20N.2.hl.TZ0.4a
Nickel catalyses the conversion of propanone to propan-2-ol.
(a)
Outline how a catalyst increases the rate of reaction.
[1]
Markscheme
provides an alternative pathway/mechanism AND lower Ea ✔
Accept description of how catalyst lowers Ea (e.g. “reactants adsorb on surface «of catalyst»”, “reactant bonds weaken «when adsorbed»”).
Examiners report
Although fairly well done some candidates did not mention that providing an alternate pathway to the reaction was how the activation energy was lowered and hence did not gain the mark.
