Daniel Ablog
Per. 6 Chemistry
3-12-09
Reaction Rates Lab Write Up
Title: Exploring Reaction Rates between HCl and Various Metals
Experimental Variables: We will be exploring the manipulated variables which are the
affects of different kinds of metals reacting with the HCl in this lab. To find the rates of
this experiment, we will find the amount of time it takes for the graduated cylinder to be
filled up with H2 gas up to the 2 mL mark.
Purpose: How does the type of metal reacting with HCl affect the rate of reaction?
Background Observations: From watching the reaction between the hydrochloric acid,
HCl, and the Zinc, Zn, from the experiment created by Mr. Howard, we observed that as
the zinc was placed into the test tube with the HCl, the reaction created a lot of bubbling
and foaming. We also found that the air bubbles or gas from the reaction transferred from
the HCl towards the graduated cylinder. The gas that was transferred into the graduated
cylinder displaced the water that was originally in the graduated cylinder. The graduated
cylinder was located inside the beaker filled with water.
Chemical Equation: Zn(s) + 2 HCl (aq)
H2 (g) + ZnCl2 (aq)
Prediction: If we change the zinc metal reacting with the HCl in this lab to other
different metals such as copper, magnesium, and tin, then the reaction time of the
different metals (copper, magnesium, and tin), with the HCl will vary from slow to fast,
because HCl has different effects on different metals, especially copper because HCl does
not create such a prominent or effective reaction with copper compared to zinc with HCl.
As far as the Collision Theory, the reason for the varied time is because of the nature of
the reactants.
Materials:
 a 10 mL graduated cylinder
 1 beaker
 1 test tube
 1 eye dropper
 rubber tubing (30 cm.)
 a one-hole rubber stopper
 a one-hole rubber stopper connected to the rubber tubing
 timing devices
 a scale or weighing device
 water
 1M HCl, hydrochloric acid
 mossy Zinc, Zn
 Magnesium, Mg ribbon


Tin, Sn
Cu wire pieces
Controlled Variables: The controlled variables in this lab, or the variables that we will
be keeping the same are the 10mL graduated cylinder, the beaker, the test tube, the eye
dropper, the rubber tubing (30 cm.), the one-hole stopper, the one-hole stopper connected
to the rubber tubing, the timing devices, the scale, the amount of water used in the beaker,
the amount of 1M HCl in the test tube, the amount of mossy zinc being tested in the test
tube with the HCl, the amount of magnesium being tested in the test tube with the HCl,
the amount of tin being tested in the test tube with the HCl, the amount of copper being
used in the test tube with the HCl, and the room temperature.
Manipulated Variable: The manipulated variable in this lab is the type of metal reacting
with the HCl inside the test tube. We will change the original zinc metal to three other
metals, all reacting with the HCl as well. These other three metals are magnesium, tin,
and copper.
Responding Variable: We will find and calculate the reaction rates of all four metals by
measuring the amount of time it will take for each reaction to fill up the graduated
cylinder (located inside the beaker filled up to about two-thirds of water) with 2 mL of
hydrogen gas accumulating inside. That can be reworded as water being displaced for 2
mL of the graduated cylinder. The responding variable in this lab is the amount of time
that each reaction takes to fill up the graduated cylinder with 2 mL of hydrogen gas.
Trials Repeated: We will use 4 different trials levels. We will repeat each trial twice.
Experimental Control Condition: All trials in our experiment will be compared to the
reaction rate of the reaction dealing with adding the zinc into the test tube filled with 1M
HCl. We will set up this controlled experiment with a beaker, a 10mL graduated cylinder,
1 test tube, rubber tubing (30 cm.), 1 eye dropper, a one-hole rubber stopper, a one-hole
rubber stopper connected to the rubber tubing, timing devices, a scale, water, 1M HCl,
hydrochloric acid, and mossy zinc. First we will set up the experiment as shown by Mr.
Howard, or as in steps 1-7 of our procedure. In this controlled experiment we will place
the 0.1 grams of zinc into the test tube full of 10mL of HCl. Simultaneously; we will start
our timing device. We will then observe how much water is displaced in the graduated
cylinder. Once the water is displaced by 2mL, we will stop our timer and record the
results.
Extra Validity Measure: To make sure that our experimental results are consistent and
accurate, we will make sure to clean out all of our beakers and glassware being used to
prepare before every new reaction. To make consistent and accurate results, we will also
make sure to be exact in our measurements when adding or displacing chemicals. For
example, we will make sure to keep the graduated cylinder full of water before removing
the one-hole rubber stopper from the graduated cylinder. During the experiment, we will
also make sure to keep the weights of all four of our different metals the same when
adding them to the HCl to make accurate results.
Logical Procedure Steps:
1. Gather all necessary materials. When you gather the zinc, magnesium, tin, and copper,
make sure that all the metals being used are all equal in weight. Make sure all the metals
weigh 0.1 grams. Put on all necessary safety gear for the lab. (Aprons and goggles)
2. Make sure materials are clean. If not, wash and rinse out all materials.
3. Fill the beaker up to about two-thirds of the beaker with water.
4. Fill the graduated cylinder up with water until it overflows. Once the graduated
cylinder overflows, take one of the one-hole rubber stoppers and plug it on the top of the
graduated cylinder.
5. Invert the graduated cylinder or turn it upside own and place it into the water, inside
the beaker.
6. While the graduated cylinder is pointing downwards in the water, gently remove the
one-hole rubber stopper so that no water seeps out of the graduated cylinder. Make sure
that you keep the graduated cylinder inside the water pointing downwards while
you remove the one-hole rubber stopper. No water should come out of the
graduated cylinder during this process. Replace the rubber stopper with the 30 cm
rubber tube while the graduated cylinder is still in the water. Make sure the tube is
placed in the graduated cylinder securely.
7. Take the HCl liquid from your teacher and pour it into the test tube. Fill up the tube up
to 10 mL of HCl.
8. Prepare the timing device. Refresh the timer to 0:00.
9. Take the mossy zinc and place the piece of zinc into the test tube filled with the 10 mL
of HCl. Quickly place the one-hole rubber stopper that is connected to the rubber tubing
onto top of the test tube with the HCl and mossy zinc. Simultaneously press the start
button on the timing device.
10. Stop the timer when the graduated cylinder (in the beaker filled with water) fills up
with 2 mL of hydrogen gas.
11. Record your results. Your results should include the time it took for the graduated
cylinder to fill up with 2 mL of hydrogen gas, observations, and the types of metals being
used. Use a table to record your information.
12. Repeat the trial for a second time from steps 2 through 10 for validity.
13. Repeat steps 2 through 11, replacing the mossy zinc being used in step 8 with the
metal magnesium ribbon. Make sure you have completed 2 trials.
14. Repeat steps 2 through 11 replacing the mossy zinc being used in step 8 with the
metal tin. Make sure you have completed 2 trials.
15. Repeat steps 2 through 11 replacing the mossy zinc being used in step 8 with the
metal copper pieces. Make sure to complete 2 trials.
16. Verify that you have taken observations and written down notes for each metal used
in the experiment.
17. Clean materials and put away all safety gear and materials.
Data Collection:
Item (metals)
Zinc, Zn
Time 1 (in
seconds) that
it took
graduated
cylinder to fill
with 2 mL of
Hydrogen gas
240 s.
Time 2 (in
seconds) that
it took
graduated
cylinder to fill
with 2 mL of
Hydrogen gas
None, N/A
Mass (in
grams)
0.1 g
Observations




Magnesium, Mg
9 s.
7 s.
0.03 g



Whitish liquid
zinc bubbled and
fizzed
Smoldering zinc
About 1 bubble
per second
Similar to pouring
baking soda into
vinegar.
Exothermic
(released heat)
Bubbling and
extreme fizzing
Tin, Sn
No reaction
No reaction
0.1 g
No reaction
Copper, Cu
No reaction
No reaction
0.1 g
No reaction
Analysis
Item
Formula
Work
Reaction
Rate of 0.1
grams of
Zinc with
10mL of HCl
(Time)/(2mL of
Hydrogen gas) =
Reaction rate
(seconds per mL)
Trial #1: (240 s.)/
(2mL of Hydrogen
gas) =
120 s./mL
Answers
(Reaction
Rates,
seconds per
mL)
Trial #1 =
120s./ mL
(120 seconds
per milliliter)
(no trial #2)
(no trial #2)
Trial #1: (9s.)/
(2mL of Hydrogen
gas) = 4.5 s./ mL
Trial #2: (7s.)/
(2mL of Hydrogen
gas) = 3.5 s./mL
Trial #1 = 4.5
s./ mL
Trial #2 =
3.5 s./mL
Reaction
Rate of 0.03
grams of
Magnesium
with 10mL of
HCl
(Time)/(2mL of
Hydrogen gas) )=
Reaction rate
(seconds per mL)
Reaction
Rate of 0.1
grams of Tin
with 10mL of
HCl
(Time)/(2mL of
Hydrogen gas) )=
Reaction rate
(seconds per mL)
Trial #1:
(no reactions)
Trial #1 = 0
Reaction
Rate of 0.1
grams of
Copper with
10mL of HCl
(Time)/(2mL of
Hydrogen gas) )=
Reaction rate
(seconds per mL)
Trial #1:
(no reactions)
Trial #1 = 0
Average
Reaction
Rates of Both
Trials
Work: 120
s./mL = Avg.
Reaction Rate
(no Trial #2)
Avg.
Reaction
Rate = 120
s./mL
(milliliters of
hydrogen gas
in the
graduated
cylinder)
Work:
(4.5s./mL)+(3
.5s./mL) = 8.0
(8.0)/2 = 4
Avg.
Reaction
Rate = 4
s./mL
0 seconds/mL
0 seconds/
mL.
Sources of Error: During this lab, we committed many sources of error that changed and
varied our results and rates that we came up with. First of all, one source of error that we
had in this lab was not being able to keep the weights of all of our different metals the
same. For example, the zinc, copper, and tin that we used all weighed 0.1 grams. The
magnesium, however, weighed 0.03 grams due to its large size with its light weight.
Another source of error that occurred in our lab was that when we removed the one-hole
stopper from the graduated cylinder while it was still in the water, some water seeped out
of the graduated cylinder. This definitely affected our results because it gave the
hydrogen displacement in the graduated cylinder an extra few more milliliters of
hydrogen gas. This made our time results quicker. Our last source of error was when we
were collecting our data. We were not able to gain information for a second trial for the
zinc and HCl reaction. This definitely affected our validity as well as accuracy in our
results.
Conclusion:
My hypothesis stated that if we change the type of metal being used with the
reaction with the 10mL of HCl instead of the zinc, then the reaction rates would vary in
time, because of all the different metals’ nature of reactants. My hypothesis came out to
be correct. The zinc that reacted with the 10mL of HCl had an average reaction rate of
120 seconds per milliliter of displaced water in the graduated cylinder. On the other hand,
the magnesium reaction with the 10mL of HCl had an average reaction rate of 4 seconds
per milliliter of displaced water in the graduated cylinder. Both the tin reaction with the
HCl and the copper reaction with the HCl had no reaction. Based on having no reactions
with the tin and the copper, we can also conclude that HCl does not have much effect on
those two metals. HCl does, however, have an effect with magnesium as well as with
zinc. These facts prove my hypothesis correct. All four of our different metals that we
experimented with had different reaction rates. The results that we observed were all due
to the Collision Theory. It was the fact that all of these four different metals that we used
each had a different nature of reactants. Each metal reacts differently to the HCl that we
used in this lab. Each of the metals that we used have different properties and hence, from
the results of the lab, they all have different reactions when it comes to reacting with HCl.
That fact now provides an answer to our essential question. The type of metal reacting
with the HCl affects the reaction rate that they make because of its different nature of
reactants. Lastly, the results that we found in this lab provide relevant connections to the
outside world. With knowing that the nature of reactants can be different in various kinds
of metal, we can use the concept of having subtle reactions by using them outside. For
example, if a certain metal has subtle reactions with chemicals that are found in
precipitation or weather, then we can use that specific metal to build sculptures or
buildings outside. With that theory, buildings would be less prone to erosion as well as
decay. Unless this theory is already being used in the real world, I do believe that this is a
relevant way of expressing the methods and properties being used in this lab.