Science 8
Chemistry Unit
Chandler Mathews
Title: Effect of HCl concentration on the rate of reaction with magnesium ribbon measured by length of
time bubbles are observed
Research Question: What is the effect of HCl concentration on the rate of reaction with magnesium
ribbon measured by length of time bubbles are observed?
Background Information:
Research the following and include in a paragraph below
 Reaction that occurs between HCl and magnesium-the reaction that occurs when they are
combined is oxidization, which is basically when it gets mixed with oxygen or goes into the air
flying around. Basically a gas.
 Identify the reactants used and the products created-When the magnesium ribbon is put into the
hydrochloric acid the magnesium will under go a change and dissolve. After the change has been
made the chemical name or something is MgCl+H2
 Any other relevant information –If it touches your skin it will cause irritation and it might harm
your skin. The acid will also bubble when you put the magnesium in it.
 Explain the relationship between concentration and reaction rate –When the concentration is
higher, which means there are more particles in the mixture, it will risk having a collision which
will therefore make the reaction rate a lot higher.
 Cite your sources used using proper citation formathttp://wiki.answers.com/Q/What_is_the_relationship_between_reactant_concentration_and_reactio
n_rates
http://wiki.answers.com/Q/What_is_the_relationship_between_reactant_concentration_and_reactio
n_rates
http://wiki.answers.com/Q/What_happens_when_you_put_magnesium_and_hydrochloric_acid_toget
her
MATERIALS:
9 X 2cm strips of magnesium ribbon
0.5M, 1M and 2M Hydrochloric acid (HCl)
3 x test tubes
Test tube rack
Stopwatch
25mL measuring cylinder
WARNING: HYDROCHLORIC ACID IS CORROSIVE, PARTICULARLY 2M
METHOD:
1. Place 3 test tubes in the test tube rack
2. Using a graduated cylinder, pour 25mL of 0.5 M HCl into each of the test tubes
3. Add one of the 2cm strips of magnesium ribbon to the first test tube
4. Using the stopwatch, measure the time the bubbles are produced and record
5. Repeat steps 3-4 in the remaining test tubes containing 0.5 M HCl
6. Dispose of materials
7. Repeat steps 1-6 for 1.0 M HCl and 2.0 M HCl
Science 8
Chemistry Unit
APPARATUS DIAGRAM:
Draw the procedure outlined above. Take care to label contents and amounts
HYPOTHESIS
I believe that the more the HCl concentration, the reaction rate wil be higher. The more molar HCl
will have the faster the reaction rate, the less molar HCl will be the slow reaction rate. This is because the
concentration effect the reaction rate in a way where the more concentration the higher the reaction rate.
Science 8
Chemistry Unit
VARIABLES
Variable
Identify the Variable
IV
HCl with different
concentration
DV
Length of time of water
bubbling
Test tubes
Graduated cylinder
CV
Magnesium ribbon
Stopwatch
Method of Variable Control
The strip of magnesium ribbon will be
dipped into the HCl with concentrations
of 0.5M, 1M and 2M. HCl will be poured
into separate test tubes.
The length of time of water bubbling will
be measured by the stopwatch
immediately after the magnesium ribbon
is dipped into the test tubes until it stops
bubbling.
25 mL of HCl would be poured into the
test tubes.
The graduated cylinder will be used to
measure the volume of HCl.
Magnesium ribbons will be cut into strips
of 2cm long and will be dipped into the
HCl.
The stopwatch will be used to measure
the how long the water bubbles.
RESULTS
QUANTITATIVE DATA: Create a data table to record your results
0.5M HCl – Average time is 12.1 minutes. (1st time, 13.42 minutes; 2nd time, 11.58 minutes; 3rd time, 11.29
minutes)
1.0M HCl – Average time is 1.8321 minutes. (1st time, 2.02 minutes; 2nd time, 1.43 minutes; 3rd time, 2.04
minutes)
2.0M HCl – Average time is 28.99 seconds. (1st time; 30.6 seconds; 2nd time, 22.03 seconds; 3rd time, 34.34
seconds)
Science 8
Chemistry Unit
QUALITATIVE DATA:
When we put the magnesium strip into the 1.0M HCl, it started steaming/smoking. The test tubes became
warmer as the magnesium strips continued to dissolve.
When we put the magnesium strip into the Steaming a LOT for 2.0M, it also got warmer as the magnesium
dissolved.
Each of the strips (when put into HCl) created a horrible smell.
DATA PROCESSING AND PRESENTATION:
Process the following data and record your processed data in a table
 The average length of time that bubbles were observed for each HCl concentration
Concentration
0.5M
1.0M
2.0M
Test Tube 1
13.42 minutes
2.02 minutes
30.6 seconds
Test Tube 2
11.58 minutes
1.43 minutes
22.03 seconds
DATA PRESENTATION:
Use Excel to plot a line graph of concentration against time.
Average Time of Reaction of Magnesium to
HCl Concentration
800
Time to Disolve in seconds
700
600
500
400
300
200
100
0
0
0.5
1
1.5
Concentration of HCl
2
2.5
Test Tube 3
11.29 minutes
2.04 minutes
34.34 seconds
Science 8
Chemistry Unit
DISCUSSION
1.In which test tube were bubbles produced the fastest?
The test tube with 2.0 concentrations the bubbles were produced the fastest but it also lasted for the
shortest time.
2.From your results, what was the effect of increasing the concentration on the rate of the reaction?
Remember to prove your point by referring to data in the table.
As you can see in the graph above, the higher the concentration the less time it took for the magnesium
ribbon to dissolve. Having this information we can say that increasing the concentration will make the rate
of reaction increase.
3.Explain the result stated above using labeled diagrams to assist your explanation
In the results stated above when the concentration was raised the time was decreased.
4. What limitations can you identify in the method used, the materials available or in the way that you
carried out the method?
We didn’t really have enough time to try it again to see if the data we collected was correct. There is also
the fact that we only used three different amounts of concentration instead of using more which would
possible show us more about our experiment.
5. What suggestions can you give to improve on the limitations you have identified?
A suggestion is to get different amounts of HCl concentration and use more time conducting this
experiment. It would also be pretty cool if we could add more than just a small trip of magnesium ribbon,
such as putting a small block of magnesium into a cup or bowl of HCl.
6. If you could do a follow-up experiment to this one, what is a further area of study that you could
pursue? State the research question or describe the experiment you would conduct.
I would try to do something exactly like this experiment but with stronger chemicals that would possibly
have a bigger reaction or a cooler one, such as a reaction that would like the surface of the liquid on fire. I
guess the research question would be the same because you are experiment on the same area of science.
CONCLUSION:
As the concentration is increased the reaction rate increases
As the concentration is decreased the reaction rate decreases
Science 8
Chemistry Unit