A manufacturer compares two batches of cube-shaped particles made from the same metal catalyst. The same mass of catalyst is used in each test, with all other conditions kept the same.
| Batch | Side length of each particle (nm) | Time for a fixed amount of product to form (s) |
|---|---|---|
| M | 60 | 180 |
| N | 15 | 48 |
Calculate the surface area to volume ratio of one particle in each batch.
Then calculate how many times larger the ratio is for batch N than for batch M.
Explain which batch is more suitable if the manufacturer wants to reduce the mass of catalyst needed while keeping the reaction at least as fast as it is with batch M.
122 exam-style questions on OCR GCSE Chemistry 2.3 Properties of materials, covering 2.3.1 Carbon bonding and the variety of organic compounds, 2.3.2 Diamond, graphite, fullerenes and graphene, 2.3.3 Bond strength, changes of state and predicting states, 2.3.4 Bulk properties and types of bonding, and 2.3.5 Nanoparticles: scale, surface area, uses and risks. Each one has a worked solution and a mark scheme showing where the marks go.