JSSS
Student
To investigate the relative reactivities of Ca, Mg, Zn and Cu
based on their reactions with water and acid
OC52
Remember what you learned in OC51 when you investigated the reaction between zinc and
hydrochloric acid and tested for hydrogen. To jog your memory, answer the following in the
spaces provided.
1. Write down the word equation and the chemical equation for that reaction.
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2. Write down in order the names of these metallic elements: Ca, Mg, and Cu.
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3. Which two of these metals belong to the group known as the alkaline earth metals.
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4. What is the group number of the alkaline earth metals?
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5. Write down the test for hydrogen gas.
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To help plan your investigation, answer the following
6. Would it be safer to react the metals first with water or to react them first with acid?
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7. How are you going to make the test fair?
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8. Write down the variables that should be kept the same (constant) for each metal.
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9. The change that we are going to make is to use a different
each time we add
water or acid.
Now we will predict what we expect to happen
10. When we react the different metals separately and in turn with both water and acid we
think that some will react
than others. From what we will observe (see), we
should be able to sort the metals into an order. We will place the most reactive metal first
and the
reactive metal
with the other two in order in between.
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JSSS
Student
The experiment
Do not carry out the experiment until you have checked with the teacher that your method is
safe. Safety glasses and gloves should be worn.
Apparatus
Graduated plastic droppers, distilled water, 3 M hydrochloric acid, Ca, Mg, Zn, Cu, well plate or
spot plate.
Possible setup
Draw a labelled diagram of your setup in the space below.
Procedure
1. From your group and class discussions, decide on the appropriate amount of each metal
to be used
2. Because of the concentration of the acid (3 M), do not use more than 3 drops each time
3. Record your observations in a table
Table recording data / observations
Zn
Mg
Ca
Cu
Observations
Observations
Observations
Observations
No gas bubbles
Water
Hydrochloric
acid
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JSSS
Student
Looking for a pattern / trend in the results / observations
1. Which metal is the most reactive of the four?
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2. Explain why you think so
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3. Which metal is the least reactive of the four?
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4. Explain why you think so
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5. Which of the two metals left is the more reactive?
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6. Explain why you think so
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Interpret and evaluate
1. Are you happy that your test was fair?
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2. How might it be improved?
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3. Our conclusion is that the order of reactivity of these four metals, starting with the most
reactive is
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4. Your group should now be ready to report back in a class discussion.
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