Hydrogen peroxide, H₂O₂, decomposes slowly to make water and oxygen.
A student adds 0.50 g of different metal oxide powders to 20 cm³ of hydrogen peroxide solution.
The student measures the volume of oxygen collected in the first 60 seconds.
The table shows the results.
| Metal oxide added | Volume of oxygen collected in 60 s (cm³) |
|---|---|
| none | 1 |
| aluminium oxide | 1 |
| copper(II) oxide | 18 |
| iron(III) oxide | 12 |
| magnesium oxide | 2 |
| manganese(IV) oxide | 64 |
Write the balanced symbol equation for the decomposition of hydrogen peroxide.
The student concludes:
"Oxides of transition metals are better catalysts for this reaction than oxides of other metals."
Evaluate the student's conclusion. Use the data in the table.
Describe how the student could show that manganese(IV) oxide is a catalyst and is not used up in the reaction.
Iron forms two oxides, iron(II) oxide and iron(III) oxide.
Write the formula of iron(III) oxide.
Explain how the existence of these two oxides shows a typical property of transition metals.
Vanadium is a transition metal.
Predict two physical properties of vanadium.
60 exam-style questions on OCR GCSE Chemistry 4.1 Predicting chemical reactions, covering 4.1.1 Properties and trends in Groups 1, 7 and 0, 4.1.2 Properties of the transition metals, 4.1.3 Reactivity predicted from position in the Periodic Table, and 4.1.4 Reactivity of metals and the reactivity series. Each one has a worked solution and a mark scheme showing where the marks go.