Ethanol is made industrially by reacting ethene with steam.
C2H4(g)+H2O(g)⇌C2H5OH(g) \mathrm{C_{2}H_{4}(g) + H_{2}O(g) \rightleftharpoons C_{2}H_{5}OH(g)} C2H4(g)+H2O(g)⇌C2H5OH(g)The forward reaction is exothermic. A phosphoric acid catalyst is used.
The company uses a temperature of 300 °C and a pressure of 60 atm.
The table shows some data for the reaction at 60 atm.
| Temperature (°C) | Ethene converted at equilibrium (%) | Relative rate of reaction |
|---|---|---|
| 200 | 31 | 1 |
| 250 | 20 | 4 |
| 300 | 12 | 13 |
| 350 | 7 | 38 |
Use the data to explain why the company uses a temperature of 300 °C.
Calculate the maximum mass of ethanol that can be made from 70.0 tonnes of ethene.
Relative atomic mass (Ar): H = 1.0, C = 12.0, O = 16.0
Give your answer to 3 significant figures.
Mass of ethanol = ...... tonnes
A manager suggests increasing the pressure from 60 atm to 200 atm.
Evaluate this suggestion.
Each time the gases pass through the reactor, only about 5% of the ethene reacts. The ethanol is removed. The unreacted ethene and steam are returned to the reactor.
Explain why the company does this.
61 exam-style questions on OCR GCSE Chemistry 6.1 Improving processes and products, covering 6.1.1 Extracting metals industrially and by electrolysis, 6.1.2 Life cycle assessment and recycling, 6.1.3 Biological methods of metal extraction, 6.1.4 The Haber process and the production of fertilisers, 6.1.5 Alloys and their uses, 6.1.6 Corrosion and its prevention, 6.1.7 Comparing and selecting materials, and 6.1.8 Industrial conditions, rate and position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.