DP Chemistry (last assessment 2024)
Question 22M.2.hl.TZ2.4d(iv)
| Date | May 2022 | Marks available | [Maximum mark: 2] | Reference code | 22M.2.hl.TZ2.4d(iv) |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Calculate | Question number | d(iv) | Adapted from | N/A |
d(iv).
[Maximum mark: 2]
22M.2.hl.TZ2.4d(iv)
Hydrogen and iodine react to form hydrogen iodide.
H2 (g) + 2 (g) 2H (g)
Consider the reaction of hydrogen with solid iodine.
H2 (g) + 2 (s) 2H (g) ΔH⦵ = +53.0 kJ mol−1
(d(iv))
Calculate the equilibrium constant, Kc, for this reaction at 298 K. Use your answer to (d)(iii) and sections 1 and 2 of the data booklet.
(If you did not obtain an answer to (d)(iii) use a value of 2.0 kJ mol−1, although this is not the correct answer).
[2]
Markscheme
«ln Kc= – (3.4 × 103 J mol–1 /8.31 J K–1 mol–1 × 298 K)» = –1.37 ✔
«Kc =» 0.25 ✔
Award [2] for “0.45” for the use of 2.0 kJ mol–1 for ΔG⦵.
