we are doing a lab in school where we test the reactiveness of copper, magnesium and zinc in solutions of copper nitrate, magnesium nitrate and zinc nitrate.my results show that copper doesn't react with any of those, zinc only with copper nitrate and magnesium with both copper nitrate and zinc nitrate.if my answers are right, can someone please explain to me why that happensthanks so much
What you are observing is a 'redox' reaction (reduction and oxidation). What is going on at the molecular level is a kind of 'competition for electrons', The most reactive elements will have the biggest tendency to get rid of their electrons. If you add copper to the solutions, since copper is the least reactive element, it will have a stronger attraction for the electrons than zinc and magnesium ions, so it will keep them, and everything will stay as it is. Zinc is more reactive than copper but less reactive than magnesium, hence it will take electrons from the magnesium, but not from the copper. If you add a piece of zinc to copper nitrate, you are putting the zinc atoms in contact with the copper ions. Since the copper ions have a stronger attraction for the electrons than the zinc ions, the electrons will transfer from the zinc to the copper, so the copper becomes solid and the zinc dissolves. When you add it to the magnesium solution, nothing happens because the magnesium ions have less of an attraction for the electrons than the zinc atoms, so the electrons will just stay with the zinc and nothing will happen. If you want to read more, do a search for metal displacement reactions, since this is the name for the reactions that are occuring. One metal displaces the other; as one metal dissolves, the other metal becomes solid again. Hope that helped, Dan.
