DP Chemistry (last assessment 2024)
Question 22M.1.sl.TZ2.14
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1.sl.TZ2.14 |
| Level | sl | Paper | 1 | Time zone | TZ2 |
| Command term | Derive | Question number | 14 | Adapted from | N/A |
14.
[Maximum mark: 1]
22M.1.sl.TZ2.14
Which combination of ΔH1, ΔH2, and ΔH3 would give the enthalpy of the reaction?
CS2 (l) + 3O2 (g) → CO2 (g) + 2SO2 (g)
ΔH1 C (s) + O2 (g) → CO2 (g)
ΔH2 S (s) + O2 (g) → SO2 (g)
ΔH3 C (s) + 2S (s) → CS2 (l)
A. ΔH = ΔH1 + ΔH2 + ΔH3
B. ΔH = ΔH1 + ΔH2 − ΔH3
C. ΔH = ΔH1 + 2(ΔH2) + ΔH3
D. ΔH = ΔH1 + 2(ΔH2) − ΔH3
[1]
Markscheme
D
Examiners report
A very well answered question using Hess’s law. 85% of the candidates used the enthalpies given to calculate the unknown enthalpy of reaction.