1.1. Hydrogen peroxide solution decomposes to give water and oxygen gas.

The equation for this reaction is:

2H₂O₂ (aq) → 2H₂O (l) + O₂ (g)

Three different solids are catalysts for the decomposition of hydrogen peroxide solution.

 A student is given hydrogen peroxide solution and a sample of each of the solid catalysts.

 The student has a timer, a measuring cylinder, a balance and the apparatus shown in the diagram.

 Describe a method the student could use to find which of the three solids is the most effective catalyst for the decomposition of hydrogen peroxide solution. 

1.2. The diagram shows the reaction profile for the decomposition of hydrogen peroxide without a catalyst.

 i) Label the diagram to show the activation energy (E_a) and the enthalpy change (ΔH) for this reaction.

 (2)

 ii) On the diagram, draw a curve to show the reaction profile for the same reaction when a catalyst is used.

 (1)