13. a) Draw a labeled diagram for an apparatus that can be used to purify copper. b) Write the anode, cathode and overall reactions for the above process. c) A 20g sample of copper was to be purified. The sample was connected to an apparatus similar to the above one, and a current of 2 A was allowed to flow for Shrs. i) Calculate the mass of copper that should deposit below the impure sample. [Cu=64,F=96000C] ii) If after this time the mass of the copper sample decreased from 20 to 5g, calculate the percentage purity of the sample