DP Chemistry (first assessment 2025)
Question 22M.1A.SL.TZ2.23
| Date | May 2022 | Marks available | [Maximum mark: 1] | Reference code | 22M.1A.SL.TZ2.23 |
| Level | SL | Paper | 1A | Time zone | TZ2 |
| Command term | Solve | Question number | 23 | Adapted from | N/A |
23.
[Maximum mark: 1]
22M.1A.SL.TZ2.23
0.50 mol of (g) and 0.50 mol of Br2 (g) are placed in a closed flask. The following equilibrium is established.
(g) + Br2 (g) 2Br (g)
The equilibrium mixture contains 0.80 mol of Br (g). What is the value of Kc?
A. 0.64
B. 1.3
C. 2.6
D. 64
[1]
Markscheme
D
Examiners report
41% of the candidates were able to calculate Kc given the initial amounts of reactants and the amount of product at equilibrium.
Syllabus sections
Reactivity 2. How much, how fast and how far? » Reactivity 2.3—How far? The extent of chemical change » Reactivity 2.3.6—The equilibrium law is the basis for quantifying the composition of an equilibrium mixture. Solve problems involving values of K and initial and equilibrium concentrations of the components of an equilibrium mixture.