DP Chemistry (last assessment 2024)
Question 22M.2.hl.TZ2.8f(ii)
Date | May 2022 | Marks available | [Maximum mark: 2] | Reference code | 22M.2.hl.TZ2.8f(ii) |
Level | hl | Paper | 2 | Time zone | TZ2 |
Command term | Draw, Label | Question number | f(ii) | Adapted from | N/A |
f(ii).
[Maximum mark: 2]
22M.2.hl.TZ2.8f(ii)
Carbon forms many compounds.
Chlorine reacts with methane.
CH4 (g) + Cl2 (g) → CH3Cl (g) + HCl (g)
(f(ii))
Draw and label an enthalpy level diagram for this reaction.
[2]
Markscheme
reactants at higher enthalpy than products ✔
ΔH/-99 «kJ» labelled on arrow from reactants to products
OR
activation energy/Ea labelled on arrow from reactant to top of energy profile ✔
Accept a double headed arrow between reactants and products labelled as ΔH for M2.
Examiners report
Most candidates drew correct energy profiles, consistent with the sign of the energy change calculated in the previous question. And again, only very weak candidate failed to get at least 1 mark for correct profiles.