CSEC Chemistry · May/June 2010 · Paper 2 · Question 1(a)(ii)

Jonathan and Karen conducted experiments on the decomposition of hydrogen peroxide using manganese(IV) oxide as a catalyst. Jonathan used 100 cm³ of 0.80 mol dm⁻³ hydrogen peroxide, measuring oxygen volume over time (Table 1). Karen used 100 cm³ of 0.40 mol dm⁻³ hydrogen peroxide, with her results shown in Figure 1. The decomposition is exothermic, producing water and oxygen. Figure 2 illustrates the enthalpy change for an exothermic reaction and the effect of a catalyst.

Write a balanced equation to show the decomposition of hydrogen peroxide by manganese(IV) oxide (MnO₂).

This question uses a figure or table from the paper — you'll see it when you practise.