brightly polished iron nails are placed in copper nitrate solution. Describe all that will be observed in one hour ?
The iron is greater reactive than copper so whilst the iron nail is immersed in copper sulphate the iron takes sulphate ion from the copper sulphate and copper metallic is deposited on suited of the iron so as that the nail will then look like a copper nail.The chemical reaction is termed a alternative reaction, and is chemically represented as : CuSO4(compound in answer) + Fe(metallic) ------>Cu(deposited metallic) + FeSO4.
The iron will displace the copper as it is more reactive and form iron nitrate solution and copper
Initially, you will see a bright blue solution and shinny iron nails. The blue color is due to hydrated copper(II) ions, [Cu(H2O)6]2+. Over time you will see the following occurring simultaneously. 1. Iron nail surface becomes dull and pitted as it is covered in dark red copper metal 2. The blue of the solution will fade as copper ions are removed from solution, to be replaced by a yellowish color due to Fe2+ ions in solution. Fe(s) + Cu2+ --> Fe2+ + Cu(s) 3. The solution will become somewhat cloudy due to the formation of Fe(OH)2 as Fe2+ reacts slightly with water. The reaction of an ion with water is called hydrolysis. Fe2+ + 2HOH --> Fe(OH)2(s) + 2H+ 4. It is difficult to distinguish from the copper that is plating out, but there may be some visible rust* forming due to the oxidation of the iron to the +3 state by dissolved oxygen. 4Fe(s) + 3O2(aq) + 6H2O(l) --> 4Fe(OH)3(s) * Rust which forms under water is Fe(OH)3 while the rust that we see on a daily basis is FeO(OH). 4Fe(s) + 3O2(g) + 2H2O(l) --> 4FeO(OH)(s) Rarely do you actually see Fe2O3 except in arid environments. The often-presented equation for the formation of rust.... 2Fe(s) + O2(g) --> 2Fe2O3(g) ... is incorrect. Actual rust requires water along with oxygen.
