A student tests some metal oxides to see which is the best catalyst for the breakdown of hydrogen peroxide. She adds 0.5 g of each oxide to 25 cm3\mathrm{cm^{3}}cm3 of hydrogen peroxide solution and measures the volume of oxygen collected in 60 s.
The table shows her results.
| Metal oxide added | Volume of oxygen collected in 60 s in cm3\mathrm{cm^{3}}cm3 |
|---|---|
| none | 2 |
| copper(II) oxide | 10 |
| iron(III) oxide | 15 |
| manganese(IV) oxide | 48 |
| zinc oxide | 2 |
State which metal oxide is the best catalyst. Give a reason for your answer.
State what the result for zinc oxide shows.
Give two variables, other than the volume of hydrogen peroxide solution and the mass of oxide, that the student should keep the same.
Explain how a catalyst increases the rate of a reaction.
Use the equation: mean rate of reaction=volume of gastime\displaystyle \text{mean rate of reaction} = \frac{\text{volume of gas}}{\text{time}}mean rate of reaction=timevolume of gas
Calculate the mean rate of oxygen production with manganese(IV) oxide, in cm3\mathrm{cm^{3}}cm3 per second.
54 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.