Paper 2 Questions

Question 1

Ethanol can be produced from ethene and steam.
The equation for the reaction is:
C2H4(g) + H2O(g) ⇌ C2H5OH(g)
The forward reaction is exothermic.
Explain how the conditions for this reaction should be chosen to produce
ethanol as economically as possible

Answer 1

• higher temperature and pressure gives higher rates because of more frequent collisions
• a catalyst can be used to give a higher rate because the activation energy is reduced
• higher temperature gives lower yield because the reaction is exothermic
• higher temperatures use more energy so costs increase