3. Why is copper plumbing used in our homes but not aluminum plumbing? 4. The average human needs 2.0 mg of copper ions, Cu2+, per day in their diet. This is how many copper ions? x 2.0mg x 12 -12 = 0.002 g 1000mg Cu 2+ 5. Copper is extracted from the ore, chalcopyrite, CuFeS. How many kilograms of a 0.862% chalcopyrite ore will be necessary to produce 1.00 kg of pure copper? The percentage of copper in chalcopyrite needs to be known to work this problem. nadsund sinoliem