In a school laboratory, ammonium sulfate is made by titrating dilute ammonia solution with dilute sulfuric acid. The solution is then evaporated to crystallise the salt.
Why would this method be too expensive for making fertiliser on a large scale?
Dilute solutions react too quickly to be controlled safely on a large scale.
The titration needs an expensive catalyst to make the reaction happen.
The salt made by this method is too impure to be used as a fertiliser.
Evaporating the water from dilute solutions would need a lot of energy.
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.