The industrial synthesis of methanol is a reversible reaction that reaches an equilibrium :
CO(g)+2H2(g)⇌CH3OH(g) \text{CO}(\text{g}) + 2\text{H}_2(\text{g}) \rightleftharpoons \text{CH}_3\text{OH}(\text{g}) CO(g)+2H2(g)⇌CH3OH(g)The forward reaction is exothermic.
The rate of attainment of equilibrium and the equilibrium yield of methanol are affected by pressure, temperature, and the presence of a catalyst.
A chemical manufacturer considered two sets of reaction conditions, X and Y.
In both setups, carbon monoxide is mixed with excess hydrogen.
Only setup Y utilizes a catalyst, along with a lower temperature and higher pressure than setup X.
The conditions for X and Y are summarized in the table below:
| Set of conditions | Pressure in atm | Temperature in °C | Catalyst |
|---|---|---|---|
| X | 50 | 380 | No catalyst used |
| Y | 100 | 250 | Copper-based catalyst used |
The manufacturer chose to operate using set of conditions Y rather than set of conditions X.
Explain, by considering the effect of changing these conditions on both the rate of attainment of equilibrium and on the equilibrium yield of methanol, why the manufacturer chose set of conditions Y.
38 exam-style questions on Edexcel GCSE Chemistry 5.2 Reversible reactions and equilibria, covering 5.2.1 Reversible reactions and dynamic equilibrium, 5.2.2 The Haber process, and 5.2.3 Changing the position of a dynamic equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.