3. (i) Briefly explain the difference between a chemicall-controlled reaction and a diffusion-controlled reaction in a heterogeneous system. (ii) The copper mineral chrysocolla occurs in many heap leach operations. It dissolves in the acidic sulphate leach solutions according to the equation CuSiO32H2O(s)+H+(aq)=SiO22H2O(s)+Cu2+(aq)+H2O The following data were obtained in a batch leach of 100um pure chrysocolla at 25C at a controlled pH of 1.0. a) Demonstrate graphically that this data is consistent with a process whose rate is controlled by diffusion within the silica product layer formed around the particles which can be assumed to be spherical. b) What experiments would enable one to distinguish between rate-controlling diffusion of protons into the product layer or copper ions out of the product layer