At first glance, both of the following reactions seem possible:

     Mg + Zn2+ ® Mg2+ + Zn
     Zn + Mg2+ ® Zn2+ + Mg

But if you think about it, one must be more likely than the other, or a beaker full of reactants will fizz forever!  Observations show that one of these will happen and one won’t.  That is because zinc and magnesium have different attractions for their valence electrons.  For any given pair of metals, one is more likely to end up in solution than the other.  It is possible to compile a list of metals in order of least to most likely to dissolve - this list is called “The Activity Series of Metals.”  The purpose of this lab is to deduce a short version of the complete list.

Some helpful hints:  If you can see a metal as a solid, then it is neutrally charged.  If it “disappears” into solution, then it has lost electrons to gain a charge.  For a given pair of metals, the one that ends up in solution is the more active.

Procedure
At the front bench are solutions containing each of the following metal ions: (actual ions may vary)
    Fe3+   Cu2+    Pb2+    Ag+    Zn2+    Mg2+    H+     Ca2+     Sn4+     Al3+

There are also samples of each of the pure metals (except for hydrogen and maybe silver).  You and your partner will assigned two of these metals.

1. Label each of eight small test tubes with a different metal you were not assigned.  Add about one inch of each solution to the matching test tube, then put a small solid sample of your metal in one.  Watch for about five or ten  minutes, and record your observations.
2. Repeat with about one-half inch of solution of your assigned metal, and solid samples of the other metals (except H and maybe Ag).  Watch for about five minutes and record your observations.
3. Repeat steps 1 and 2 with your other metal.
4. Write out the reactions for each combination.  If no reaction occured, write NR for the products.  If a metal dissolved, it gained the charge shown in the list above.
5. Share data with the rest of the class.  Sort the metals out from least active (never ends up in solution) to most active (always ends up in solution).

What To Pass In
On the back of this sheet, show the following:
 1.    The usual title stuff, andthe purpose of the experiment.
 2.    All of the equations for your chemical's reactions (there should be about 15)
 3.    The list of elements, in the order determined in #5 above.

[Activity Series #2 score sheet][MHS Chem page]