copper

1. Iron nail copper Salt solution V Add 5 drops of ferroxyl indicator at each electrode Repeat using fresh salt water and zinc instead of copper. Write down what you see for each.

2. When iron is attached to copper through the meter the ferroxyl indicator turns blue around the iron showing that there is a lot of rust. When iron is attached to zinc through the meter the ferroxyl indicator shows no blue around the iron. In fact there is a trace of red. Conclusions Copper which is below iron in the reactivity series encourages it to rust. Iron sends electrons to copper and the change Fe --> Fe2+ + 2e- is encouraged. Zinc which is above iron in the series prevents it from rusting. It sends electrons to iron and prevents Fe --> Fe2+ + 2e- from happening.

3. When iron is connected to a metal above it in the electrochemical series it is protected from rusting because electrons flow from the metal higher in the electrochemical series to iron. When iron is connected to a metal lower in the electrochemical series it rusts more quickly because electrons flow from the iron to the metal lower in the electrochemical series. Metals above iron in the series protect it from rusting. Metals below iron in the series make it rust faster.

4. When iron rusts the first change is: Fe --> Fe2+ + 2e- Loss of electrons Oxidation This is the reverse of a reaction in the Electrochemical Series. Oxygen and water are needed for rusting to occur. They accept electrons in the reaction shown Reduction