A water-treatment process uses a solid catalyst to speed up the breakdown of an unwanted substance. Two batches of the catalyst contain separate cubic particles of the same substance. All six faces of every particle are exposed. Equal masses of the two batches have equal total volumes.
| Batch | Length of each side of a particle in nm\text{nm}nm |
|---|---|
| P | 48 |
| Q | 12 |
Tests show that samples providing the same total exposed catalyst surface area give the same reaction rate. A 20.0 g sample of batch P gives the required reaction rate.
Explain how the surface area to volume ratio of a particle from batch Q compares with that of a particle from batch P.
Use the data in the table.
Explain why a smaller mass of batch Q is predicted to give the required reaction rate.
Calculate the mass of batch Q predicted to give the same reaction rate as 20.0 g of batch P.
104 exam-style questions on AQA GCSE Chemistry 2.4 Bulk and surface properties of matter including nanoparticles, covering 2.4.1 Sizes of particles and their properties and 2.4.2 Uses of nanoparticles. Each one has a worked solution and a mark scheme showing where the marks go.