Compound T is made from two gaseous reactants in a sealed reactor. In four experiments, mixtures containing the same amounts of reactants were left to reach equilibrium at different temperatures, with the pressure kept at 90 atmospheres. The results are recorded below.
| Temperature in ∘C^\circ\text{C}∘C | Percentage yield of T in % |
|---|---|
| 260 | 18 |
| 360 | 34 |
| 460 | 51 |
| 560 | 65 |
A manager wants to make T as quickly as possible and with the highest possible equilibrium yield.
Which temperature from the table should be chosen, and why?
560 ∘C^\circ\text{C}∘C, because the forward reaction is endothermic and the rate is fastest at this temperature
260 ∘C^\circ\text{C}∘C, because the forward reaction is exothermic and is favoured by a low temperature
360 ∘C^\circ\text{C}∘C, because a compromise temperature is needed to balance the yield and the rate
560 ∘C^\circ\text{C}∘C, because the forward reaction is exothermic and the rate is fastest at this temperature
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.