A-LevelChemistryEquilibria9701/12 · Feb/Mar 2022 · Q121 Mark

Hydrogen and iodine react to form hydrogen iodide in an exothermic reaction. The equation is shown. H₂(g) + I₂(g) ⇌ 2HI(g) A 1 m³ reaction vessel contains H₂, I₂ and HI gases at equilibrium. The temperature is changed such that the total pressure in the 1 m³ vessel doubles. What is the effect on the value of Kp and on the position of equilibrium? [Figure 12.1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

Adecreases, moves left

Bincreases, moves right

Cno change, moves left

Dno change, no change

✓ Correct answer

A: decreases, moves left

Oracle Prep sorts past-paper questions by topic, so you can drill Equilibria and see which topics are most likely to come up next.

Topic: Equilibria, A-Level Chemistry (syllabus 9701). Multiple choice, 1 mark.
Source: A-Level Chemistry, Feb/Mar 2022 Paper 1 Variant 2, question 12.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content