A chemist investigates this reversible reaction in separate identical sealed containers.
J2(g)+K2(g)⇌2JK(g)\text{J}_2\text{(g)} + \text{K}_2\text{(g)} \rightleftharpoons 2\text{JK(g)}J2(g)+K2(g)⇌2JK(g)
Each container initially contains 1.00 mol of J2\text{J}_2J2 and 1.00 mol of K2\text{K}_2K2, with no JK\text{JK}JK.
The table shows the amount of JK\text{JK}JK when equilibrium is reached at each temperature.
| Temperature in K | Amount of JK\text{JK}JK at equilibrium in mol |
|---|---|
| 300 | 1.64 |
| 400 | 1.18 |
| 500 | 0.72 |
Use the data to explain whether the forward reaction is exothermic or endothermic.
The mixture at equilibrium at 500 K is cooled to 350 K. Explain what happens to the amount of J2\text{J}_2J2 as a new equilibrium is reached.
109 exam-style questions on AQA GCSE Chemistry 6.2 Reversible reactions and dynamic equilibrium, covering 6.2.1 Reversible reactions, 6.2.2 Energy changes and reversible reactions, 6.2.3 Equilibrium, 6.2.4 The effect of changing conditions on equilibrium, 6.2.5 The effect of changing concentration, 6.2.6 The effect of temperature changes on equilibrium, and 6.2.7 The effect of pressure changes on equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.