DP Chemistry (last assessment 2024)
Question 19M.3.sl.TZ2.c
Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.sl.TZ2.c |
Level | sl | Paper | 3 | Time zone | TZ2 |
Command term | Explain | Question number | c | Adapted from | N/A |
c.
[Maximum mark: 2]
19M.3.sl.TZ2.c
Metals are extracted from their ores by several methods, including electrolysis and reduction with carbon.
Explain the action of metals as heterogeneous catalysts.
[2]
Markscheme
Any two of:
reactant(s) adsorb onto active sites/surface [✔]
bonds weakened/broken/stretched «in adsorbed reactants»
OR
activation energy lowered [✔]
products desorbed [✔]
Note: Accept “products released” for M3.
Examiners report
This question was reasonably answered with many candidates receiving a mark for the action of a catalyst. Teachers should remind students to use the terms adsorb/desorb with this type of process, not absorb.
