An industrial chemical is made in batches. Each batch produces 300 kg of product.
A process engineer compares operation with and without a catalyst.
| Process | Operating temperature in ∘C^\circ\mathrm{C}∘C | Time for one batch in minutes | Electrical energy used per batch in kWh |
|---|---|---|---|
| Without a catalyst | 420 | 60 | 780 |
| With a catalyst | 300 | 60 | 520 |
Electricity costs £0.24 per kWh. One charge of the catalyst costs £600. The catalyst is recovered after each batch and can be reused for all 50 batches.
Calculate the overall saving in operating cost from using the catalyst for the first 50 batches.
Use only the electricity and catalyst costs given.
Explain how using the catalyst allows the same mass of product to be made in the same time at a lower operating temperature.
122 exam-style questions on OCR GCSE Chemistry 5.2 Controlling reactions, covering 5.2.1 Measuring and interpreting rate of reaction, 5.2.2 Factors affecting rate and collision theory, and 5.2.3 Catalysts, activation energy and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.