DP Chemistry (last assessment 2024)
Question 19N.2.hl.TZ0.3c(ii)
Date | November 2019 | Marks available | [Maximum mark: 3] | Reference code | 19N.2.hl.TZ0.3c(ii) |
Level | hl | Paper | 2 | Time zone | TZ0 |
Command term | Determine | Question number | c(ii) | Adapted from | N/A |
c(ii).
[Maximum mark: 3]
19N.2.hl.TZ0.3c(ii)
Propene is an important starting material for many products. The following shows some compounds which can be made from propene, C3H6.
Propene (C3H6) → C3H7Cl → C3H8O → C3H6O
(c(ii))
Determine the enthalpy of combustion of this compound, in kJ mol−1, using data from section 11 of the data booklet.
[3]
Markscheme
bonds broken:
7(C–H) + C–O + O–H + 2(C–C) + 4.5(O=O)
OR
7(414 «kJ mol−1») + 358 «kJ mol−1» + 463 «kJ mol−1» + 2(346 «kJ mol−1») + 4.5(498 «kJ mol−1») / 6652 «kJ» ✔
bonds formed:
6(C=O) + 8(O–H)
OR
6(804 «kJ mol−1») + 8(463 «kJ mol−1») / 8528 «kJ» ✔
«ΔH = bonds broken − bonds formed = 6652 – 8528 =» −1876 «kJ mol−1» ✔
NOTE: Award [3] for correct final answer.
