DP Chemistry (last assessment 2024)
Question 19N.2.sl.TZ0.c(ii)
Date | November 2019 | Marks available | [Maximum mark: 3] | Reference code | 19N.2.sl.TZ0.c(ii) |
Level | sl | Paper | 2 | Time zone | TZ0 |
Command term | Determine | Question number | c(ii) | Adapted from | N/A |
c(ii).
[Maximum mark: 3]
19N.2.sl.TZ0.c(ii)
The following shows some compounds which can be made from ethene, C2H4.
ethene (C2H4) → C2H5Cl → C2H6O → C2H4O
Determine the enthalpy of combustion of the organic product in (b), in kJ mol−1, using data from section 11 of the data booklet.
[3]
Markscheme
bonds broken:
5(C–H) + C–C + C–O + O–H + 3(O=O)
OR
5(414«kJ mol−1») + 346«kJ mol−1» + 358«kJ mol−1» + 463«kJ mol−1» + 3(498«kJ mol−1») / 4731 «kJ» ✔
bonds formed:
4(C=O) + 6(O–H)
OR
4(804«kJ mol−1») + 6(463«kJ mol−1») / 5994 «kJ» ✔
«ΔH = bonds broken − bonds formed = 4731 − 5994 =» −1263 «kJ mol−1» ✔
NOTE: Award [3] for correct final answer.
