A. Title: The Relationship between the Type of Metal and Reactivity
Due Date: Friday April 26th, 2013
B. Aim:
What is the order of the most to the least reactive metal in the metals: iron, aluminum, copper,
magnesium, and zinc?
C. Variables:
Table 1: Variables of the Investigation
Identify the
variable(s)
Changed? Measured? Controlled?
Type of Metal
How will the variable be changed?
Independent
variable
Hydrochloric acid will be dripped onto each of the five different
metals: iron, aluminum, copper, magnesium, and zinc.
Reactivity
Observe whether the metals have a large or small reactivity and record
the observations in a tablet. The observations would be based on
things such as color, hardness, etc. Then, rank the reactivity from the
most to the least reactive.
Dependent
variable
Controlled
variables/
constants
(write at
least three)
How will the variable be measured?
Surface Area of
the Metals
How will the variables be controlled?
Amount of Acid
1 drop from the pipette would be dripped every time on each of the
metals.
Type of Acid
Concentrated hydrochloric acid will be used every time for each of the
metals.
Temperature
of Acid
The same acid from the same bottle will be used throughout the whole
experiment in the same room without heating or cooling it.
Room
Temperature
The whole experiment will be done in the same room with a
temperature of 20℃ - 25℃.
The same amount (1 drop from the pipette) of hydrochloric acid will be
dripped straight down onto each of the metals, covering the same
surface area for them all.
Equipment
The same equipment will be used throughout the whole experiment.
D. Hypothesis:
If hydrochloric acid is dripped onto each of the five metals, iron, aluminum, copper and zinc, then the
reactivity order would be magnesium, aluminum, zinc, iron, and copper from the most to the least
reactive because the number of gained / lost electrons in the outer shell is in this order from the least to
the most. Magnesium gains 2 electrons, aluminum gains 3 electrons, zinc gains 4 electrons, iron gains 9,
and copper gains the most.
E. Equipment:
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1 tablet for recording
1 pipette full of concentrated hydrochloric acid
1 piece of iron
1 piece of aluminum
1 piece of copper
1 piece of magnesium
1 piece of zinc
1 chemistry plate
1 tweezer
1 weigher
F. Method:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Gather materials.
Start videoing the experiment.
Weigh each of the 5 metals; iron, aluminum, copper, magnesium, and zinc using the weigher.
Record the masses into the tablet as quantitative data.
Place each of the 5 metals into a separate section in the chemistry plate.
Drip 1 drop of hydrochloric acid from the pipette onto the center of iron.
Observe the reaction.
Record the qualitative observations into the tablet.
Repeat steps #6 – 8 four more times for each of the other metals; aluminum, copper,
magnesium, and zinc.
Weigh each of the 5 metals; iron, aluminum, copper, magnesium, and zinc using the weigher.
*safety tip: Use the tweezer to move the metals.
Record the masses into the tablet as quantitative data.
Stop videoing the experiment.
Clean up.
G. Diagram of Apparatus:
H. Data Collection
Table 2: Quantitative Data on the Reactivity of the Five Metals with Hydrochloric Acid
Mass Before
the Reaction
(g)
Mass After the
Reaction
Mass
Difference
Iron
0.16
Aluminum
0.05
Copper
0.16
Magnesium
0.64
Zinc
0.15
0.17
0.06
0.15
0.64
0.15
+0.01
+0.01
-0.01
0
0
Table 3: Qualitative Data on the Reactivity of the Five Metals with Hydrochloric Acid
Observations
Iron
The color
slightly
became
lighter, but the
difference is
not very visible
by the naked
eye.
Aluminum
The color
slightly
became
lighter, but the
difference is
not very visible
by the naked
eye.
Copper
The color
became a little
lighter.
Magnesium
The color
became
lighter.
Zinc
It fizzed and
gas was
produced.
Smoke came
out. The color
became
lighter. It
became a little
easier to
break.
I. Processing and Presenting Data
Table 4: Order of the Reactivity of the Five Metals with Hydrochloric Acid
1
2
3
4
5
Zinc
Magnesium
Copper
Aluminum
Iron
Order of Reactivity (Most to Least)
The Reactivity of the Five Metals with
Hydrochloric Acid
5
4
3
2
1
0
Zinc
Magnesium
Copper
Aluminum
Iron
Type of Metal
J. Conclusion
In conclusion, the reactivity of the five metals with hydrochloric acid is in this order: zinc, magnesium,
copper, aluminum, and iron. This was determined based on the observations from the qualitative data
table and where things weren’t clear, such as the order of Aluminum and Iron, the video of the
experiment was viewed. The results do not support the hypothesis. In the hypothesis, the order of
reactivity was magnesium, aluminum, zinc, iron, and copper, yet the results proved this wrong. However,
based on research, the order of reactivity is in fact correct the way it was in the hypothesis. The way it
turned out in the experiment was a little different due to the lack of accuracy. This includes things such
as the fact that the metals used in the experiment were not a perfectly pure substance. Aluminum foil,
for instance, is not 100% pure aluminum. It consists of 97% aluminum and 3% paper and plastic which in
fact reduces the reactivity. Another element that reduced the accuracy was the fact that the
hydrochloric acid was very weak, with it being only 0.5% concentrated. The amount that was used was
also very little, since it was only 1 small drop from the pipette. This made it difficult to observe since the
reaction was very small. The reactivity in the experiment may have actually been in the order as it was
in the hypothesis, but it was very hard to figure that out since all the reactions themselves were very
small. There were also a several sources of error. The biggest error was that there was only one trial for
each combination and that there weren’t multiple trials as was supposed to. Another error was the fact
that even though the same amount of hydrochloric acid was dripped onto each of the 5 metals, the
surface area was not exactly the same because some metals such as iron were too thin and some of the
acid didn’t touch the metal and went down in the hole instead. These things also made the experiment
less accurate.
Additional quantitative data that was found throughout this experiment was the mass of each of the
metals before and after the reaction. Before the reaction, ironed weighed 0.16 grams, aluminum
weighed 0.05 grams, copper weighed 0.16 grams, magnesium weighed 0.64 grams, and zinc weighed
0.15 grams. After the reaction, iron weighed 0.17 grams, aluminum weighed 0.06 grams, copper
weighed 0.15 grams, magnesium weighed 0.64 grams, and zinc weighed 0.15 grams. This means that
throughout the reaction, iron and aluminum gained 0.01 grams, copper lost 0.01 grams, and magnesium
and zinc stayed the same.
This experiment is related to what we are learning (or was learning) in class. Our previous unit was
particles where we learnt about things such as the elements, chemical bondings, and reactions, which
are all related to this. Information learned in this lab can be used in the real world. For example, acid
rain can dissolve metals, one very well-known example being statues. In the real world, many statues
can been seen melted down due to acid rain. However, there is actually thought being put into these
statues too and the type of metal being used is considered well. For most metal statues, copper is being
used. This is because it is the least reactive to acid. Therefore, even though it is still reactive to acid rain,
it is not as worse as it would be when other metals such as magnesium, which is extremely reactive, is
used.
This lab has been very interesting and there are still things that are of interest in the topic. These include
things such as the reactivity with acid in other metals than the 5 we experimented on, and the reactivity
of the metals on other substances other than acid. It would be a good idea to change this lab in a way
that we can learn these things too.
K. Evaluation
The hypothesis was valid because it was testable. It included both dependent and independent variables.
It also contained quantitative values that ensured that it could be measured. The method was also valid
because it allowed for the collection of enough data to answer the question. The one measuring
instrument used in this experiment was a weigher and that measured what it was supposed to; the
weight of all 5 metals before and after. There were no silly mistakes in the way the measuring
instruments were used such as a thermometer being used to measure length. The method was also
written in a way that would be a fair test because only one variable was changed which was the
independent variable; the type of metal. It controlled all the other controlled variables. However, the
method does not say to repeat the investigation multiple times. Having more than one trial will give
more complete data, and make it more accurate.
Table 5: Identified Weaknesses and Suggestions for Realistic Improvements
Weakness
Improvement
Not pure metals
Acid too weak
Not enough acid used
Only 1 trial
Different surface areas
Instead of using metals which aren’t perfectly
pure, pure metals should be used. This would
make it more accurate.
Instead of using weak hydrochloric acid with a
concentration of only 0.5%, stronger hydrochloric
acid with a concentration of at least 1% should be
used. This would make the reaction bigger and
easier to see and therefore more accurate.
However, in this case, as a safety precaution,
gloves should be worn too.
Instead of only having 1 drop from the pipette of
hydrochloric acid, around 5 drops should be
dripped onto the metals. This would make the
reaction bigger and easier to see and therefore
more accurate.
Instead of having only 1 trial, there should be
multiple trials, possibly 3. This would make it more
accurate.
Instead of using thin metals such as a nail for iron
and a thin piece for magnesium, all the metals that
are used should have a decent amount of surface
area for all of the hydrochloric acid to drip onto.
This would make the surface areas the same and
make it more accurate.
Criterion B: Inquiring and designing
Maximum: 8
Students should be able to:
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outline an appropriate problem or research question to be tested by a scientific investigation
state a testable prediction and outline it using scientific reasoning
identify how to manipulate the variables, and outline how data will be collected
design scientific investigations.
Achievement
level
Level descriptor
The student does not reach a standard described by any of the descriptors
given below.
0
The student:
 is able to select a problem or question
 attempts to state a testable hypothesis
 is able to state variables
 attempts to design a method.
The student:
1-2
 attempts to state a problem or question
 is able to state a testable prediction
 is able to state how to manipulate the variables, and state data will be collected
 is able to design a safe method in which he or she selects materials and
The equipment.
student:
3-4
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is able to state a problem or question
is able to state and outline a testable prediction
is able to outline how to manipulate the variables, and state relevant data will
be collected
 is able to design a complete and safe method in which he or she selects appropriate
materials and equipment.
The student:
5-6
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7-8
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is able to outline a problem or question
is able to state and outline a testable prediction using correct scientific
reasoning
is able to identify how to manipulate the variables, and outline how sufficient,
relevant data will be collected
is able to design a logical, complete and safe method in which he or she selects
appropriate materials and equipment.
Command terms
Design
Produce a plan, simulation or model
Identify
Provide an answer from a number of possibilities. Recognize and state briefly a distinguishing fact
or feature
Outline
Give a brief account
Recall
Remember or recognize from prior learning experiences
Select
Choose from a list or group
State
Give a specific name, value or other brief answer without explanation or calculation
(Command terms in the Meddle Years Programme, December2010: 7-9)
Notes
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To state and outline a prediction using scientific reasoning requires students to include in their
explanations the scientific concepts, theories or understanding that support their thinking on why or
how something might happen the way they have predicted.
When students design a scientific investigation they should develop a method that will allow them
to collect sufficient data so that the problem or question can be answered.
To allow students to design scientific investigations independently, teachers must ensure that they
provide students with an open-ended problem to investigate. An open-ended problem is one that
has several independent variables from which students are able to select one as a suitable basic for
the investigation. This should ensure that students formulate a range of plans and that there is
sufficient scope to identify both independent and controlled variables.
In order to achieve the highest level for the descriptor strand in which students are asked to design
a logical, complete and safe method, the student would include only the relevant information,
correctly sequenced.
Criterion C: Processing and evaluating
Maximum: 8
Students should be able to:
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present collected and transformed data
interpret data and outline results using scientific reasoning
examine the validity of a hypothesis based on the outcome of the scientific investigation
examine the validity of the method
identify improvements or extensions to the method.
Achievement
level
0
1-2
3–4
Level descriptor
The student does not reach a standard described by any of the descriptors
below.
The student:

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
is able to collect and present data in numerical and/or visual forms
is able to interpret data
attempts to state the validity of a prediction based on the outcome of a
scientific investigation
 attempts to state the validity of the method based on the outcome of a
scientific investigation
 attempts to state improvements or extensions to the method that would
benefit the scientific investigation.
The student:
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

is able to collect and present data in numerical and/or visual forms correctly
is able to interpret data and outline the results accurately
is able to state the validity of a prediction based on the outcome of a scientific
investigation
 is able to state the validity of the method based on the outcome of a scientific
investigation
 is able to state improvements or extensions to the method that would benefit
the scientific investigation.
The student:

5-6
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
is able to collect, organize and present data in numerical and/or visual forms
correctly
is able to accurately interpret data and describe results using scientific
reasoning
is able to identify the validity of a hypothesis based on the outcome of a
scientific investigation
is able to identify the validity of the method based on the outcome of a
scientific investigation

is able to identify improvements or extensions to the method that would
benefit the scientific investigation.
The student:


7-8
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

is able to collect, organize, transform and present data in numerical and/or
visual forms correctly
is able to accurately interpret data and outline results using correct scientific
reasoning
is able to examine the validity of a prediction based on the outcome of a
scientific investigation
is able to examine the validity of the method based on the outcome of a
scientific investigation
is able to identify improvements or extensions to the method that would
benefit the scientific investigation.
Command terms
Examine
Consider an argument or concept in a way that uncovers the assumptions and interrelationships
of the issue
Identify
Provide an answer from a number of possibilities. Recognize and state briefly a distinguishing
fact or feature
Interpret
Use knowledge and understanding to recognize trends and draw conclusions from given
information
Outline
Give a brief account
Present
Offer for display, observation, examination or consideration
State
Give a specific name, value or other brief answer without explanation or calculation
( Command terms in the Middle Years Programme, December 2010: 7-9)
Notes
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The strand asking students to state/outline/examine the validity of a prediction based on the
outcome of a scientific investigation only applies to tasks in which both criteria B and C are assessed.
Transforming data involves processing raw data into a form suitable for visual representation. This
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process may involve, for example, combining and manipulating raw data (by adding, subtracting,
squaring or dividing) to determine the value of a physical quantity and also taking the average of
several measurements. It might be that the data collected are already in a form suitable for visual
representation- in the case of the distance travelled by a woodlouse, for example. If the raw data
are represented in this way and a best-fit line graph is drawn, the raw data have been processed.
Numerical forms may include mathematic calculations such as averaging, or determining values
from a graph or table.
Visual forms may include drawing graphs of various types appropriate to the kind of data being
displayed (line graphs, bar graphs, histograms, pie charts, and so on).
Qualitative data refers to non-numerical data or information that is difficult to measure in a
numerical way.
Qualitative data refers to numerical measurements of the variables associated with the
investigation.
Presentation of data includes the correct use of units; where applicable, this factor must be present
in order for students to reach to reach the highest level.
Validity of the method refers to whether the method allows for the collection of sufficient valid data
to answer the question. This includes factors such as whether the measuring instrument measures
what it is supposed to measure, the conditions of the experiment and the manipulation of variables
(fair testing).