Hydrogen peroxide decomposes slowly at room temperature.
2H2O2(aq)→2H2O(l)+O2(g)\mathrm{2H_{2}O_{2}(aq)} \rightarrow \mathrm{2H_{2}O(l)} + \mathrm{O_{2}(g)}2H2O2(aq)→2H2O(l)+O2(g)
A student wants to find out whether copper(II) oxide powder is a catalyst for this reaction.
Devise an experiment the student could carry out to show whether copper(II) oxide is a catalyst for this reaction. Your answer should include how the results would show whether it is a catalyst.
In one experiment, 50.0 cm3\mathrm{cm^{3}}cm3 of hydrogen peroxide solution decomposes completely and produces 120 cm3\mathrm{cm^{3}}cm3 of oxygen at room temperature and pressure. Calculate the concentration of the hydrogen peroxide solution in mol dm−3\mathrm{mol\,dm^{-3}}moldm−3. One mole of any gas occupies 24 000 cm3\mathrm{cm^{3}}cm3 at room temperature and pressure.
The student adds 0.50 g of copper(II) oxide. After the reaction she filters, washes and dries the solid and finds its mass is 0.47 g. Suggest why the mass is slightly lower, even though copper(II) oxide is a catalyst.
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.