The following data were obtained for the pressure leaching of a chalcopyrite concentrate having roughly spherical particles of size 75m at 90C in a sulphuric acid solution of pH2 using different pressures of oxygen. (a) Assuming that elemental sulphur is the product of oxidation, write a balanced chemical reaction for the leaching reaction. (5) (b) Using the data at 840kPa, show that the results are consistent with a reaction whose rate is controlled by that of a slow chemical reaction. (5) (c) Assuming that the solubility of oxygen is proportional to its partial pressure, estimate the order of the reaction with respect to the oxygen concentration