IDENTIFYING CHEMICAL ACITIVITY
Introduction: Silver and Gold Coins Recovered from Ocean Shipwreck is a possible news
headline, while, Iron Coins Recovered would be less likely to appear. The differences in reactivity
among metals is very important in selecting building materials and the types of products we use. In
this experiment, the student will determine the relative reactivity of several metallic elements:
copper, zinc, iron and magnesium.
Safety: Wear goggles throughout the experiment. Also dispose of the metals in the waste basket
and the solutions down the drain. Wash your hands before leaving the laboratory.
Materials: various aqueous solutions, various metals, test plate, pipettes
Terms:
Ions in solution: CuCl2(aq) == Cu 2+; ZnCl2(aq) == Zn2+; MgCl2(aq) == Mg2+; FeCl3(aq) == Fe3+
Metals: Cu(s); Zn(s); Mg(s); Fe(s)
Procedure:
Part 1: Teacher demonstration
Your teacher will demonstrate the reaction between copper metal and silver nitrate solution,
AgNO3(aq). Record your observations at these time intervals: Start, Two minutes, Ten
minutes, and Next Day.
Part 2: Comparing the Activity of Two Metals: Cu and Mg
Certain metals are more chemically active than others. You can rank the reactivates of
metals by comparing their behavior in the presence of the ions of other metals.
1. Fill two separate wells in the 24-well plate half-full with 0.5 M copper (II) chloride
solutions, CuCl2(aq).
2. Place a small piece of magnesium metal, Mg(s), into the solution in one well and a small
piece of copper metal Cu(s), into the second well.
3. Fill two separate wells in the 24-well plate half-full with 0.5 M magnesium (II) chloride
solutions, MgCl2(aq).
4. Place a small piece of magnesium metal, Mg(s), into the MgCl2(aq) solution in one well
and a small piece of copper metal Cu(s), into the second well.
5. Observe, describe and record what occurs in each well in a data table like the one below
but larger.
Mg
Cu
MgCl2(aq)
CuCl2(aq)
Part 3: Comparing the Activity of Four Metals: Cu; Mg; Zn and Fe
1. You will be given solutions containing the ions magnesium (Mg2+); iron (III) (Fe3+),
Copper(II) (Cu2+) and zinc (Zn2+), and the corresponding metals of magnesium (Mg(s)),
iron (Fe(s)), copper (Cu(s)) and zinc (Zn(s)).
2. Using these chemicals and the 24-well plate, create and complete a procedure that will
enable you to determine and rank the assigned metals in terms of their ability to replace
the other ions in solution. Record your results in a data table that is larger than the one
below.
Mg
Fe
Cu
Zn
MgCl2(aq)
FeCl3(aq)
CuCl2(aq)
ZnCl2(aq)
Data Analysis and Concept Development
Part 1:
1. List all evidence suggesting that a chemical reaction occurred when copper metal was
placed in the silver nitrate solution.
2. What happened to the number of silver ions in the solution at the end of one day as
compared to the number of silver ions in solution initially?
3. How are the physical properties of silver ions different from those of the silver atoms
produced?
4. Which metal ion could be responsible for the solution color observed at the end of the
copper and silver nitrate demonstration in Part 1? What was the source of these ions?
Part 2:
1. Does Cu metal react with Cu2+ solution?
2. Does Mg metal react with Cu2+ solution?
3. Does Mg metal react with Mg2+ solution?
4. Which metal (Cu or Mg) is more active? Justify your answer.
5. Explain what happened in the replacement reaction that occurred.
Part 3:
1. Why were the metals polished before the testing in the experiment?
2. What visible changes, if any, occurred in the following combinations?
a. zinc metal and zinc chloride
b. zinc metal and iron(III) chloride
c. iron metal and copper(II) chloride
3. Rank order the four metals from most reactive to least reactive.
Implications and Applications
1. For the copper wire and silver nitrate reaction in Part 1, draw a set of diagrams (using
different symbols for each type of element) to show what happens to individual atoms
or ions as the reaction proceeds. Be sure to label all parts of your drawings.
2. Using correct chemical symbols, write balanced equations for the reactions between the
following materials. Assume that iron forms iron (III) ions in solution, If no observable
reaction occurs, write no reaction.
a. zinc metal and copper(II) chloride solution
b. iron metal and copper(II) chloride solution
c. magnesium metal and zinc chloride solution
d. copper metal and zinc chloride solution