Four sealed vessels each contain a different gaseous reaction mixture at equilibrium.
| Vessel | Equation | Energy change of the forward reaction |
|---|---|---|
| 1 | A2(g)+B2(g)⇌2AB(g)\mathrm{A_2(g) + B_2(g) \rightleftharpoons 2AB(g)}A2(g)+B2(g)⇌2AB(g) | exothermic |
| 2 | 3C2(g)⇌2C3(g)\mathrm{3C_2(g) \rightleftharpoons 2C_3(g)}3C2(g)⇌2C3(g) | endothermic |
| 3 | 2D2(g)+E2(g)⇌2D2E(g)\mathrm{2D_2(g) + E_2(g) \rightleftharpoons 2D_2E(g)}2D2(g)+E2(g)⇌2D2E(g) | exothermic |
| 4 | F2G2(g)⇌F2(g)+G2(g)\mathrm{F_2G_2(g) \rightleftharpoons F_2(g) + G_2(g)}F2G2(g)⇌F2(g)+G2(g) | endothermic |
The temperature and pressure in every vessel are both lowered. In which vessel do both changes shift the position of equilibrium towards the reactants?
Vessel 1
Vessel 3
Vessel 4
Vessel 2
124 exam-style questions on OCR GCSE Chemistry 5.3 Equilibria, covering 5.3.1 Reversible reactions and dynamic equilibrium and 5.3.2 Changing the position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.