1. Elly Lee
December 2012– January 2013
Effect of
Temperature on
Reaction Rate
Elly Lee (10A)
2012.12– 2013.01

2. Elly Lee
December 2012– January 2013
Contents
- Title
- Introduction
- Purpose
- Research Question
- Hypothesis
- Variables
- Materials
- Experimental Procedure
- Raw Data
- Data
- Observation
- Conclusion
- Evaluation

3. Elly Lee
December 2012– January 2013
Title
Effect of Temperature on Reaction Rate
Introduction:
Chemical reactions occur at different speeds. The explosion of fireworks is
instantaneous, but the rusting of an iron gate is relatively slow. In most situations,
people would like to make the rusting of iron proceed as slowly as possible. On the
other hand, a chemical company might want to speed up the reactions that produce the
chemicals they sell. In order to understand how the rates of chemical reactions can be
controlled, it is necessary to understand the factors that influence the rates of chemical
reaction.
Purpose:
The purpose of this lab is to observe the effects of temperature on the rates of
chemical reactions.
Research Question:
How does temperature affect reaction rates?
Hypothesis:
As the temperature of HCl increases, the reaction rate of zinc metal gets faster.
- As the temperature of water increases, the water molecules get much more
active. On the other hand, as the temperature water decreases, the movement
of the water molecules becomes much slower. Since water and HCl are both
liquid, I think HCl would bring similar results. Based on this fact, I predict
that as the temperature of the HCl increases, the reaction rate of zinc metal
would get much faster.
Variables:
Independent Variable Dependent Variable Controlled Variable
Temperature The Reaction Time 1. Size of container
2. Shape of container
3. the acidity of the HCl
4. Size of Zinc

4. Elly Lee
December 2012– January 2013
Materials:
Safety Goggles
Gloves
Aprons
6.0 MolarHCl
Timer
Zinc strips
5 Test tubes
Steel Wool
Thermometer (0 0.5oC~100 0.5oC, line in every 1 degree)
250ml ( 0.5ml)Beaker
10 ml ( 0.5ml) Graduated Cylinder
Experimental Procedure:
1. Pour 5.0 ml of 6.0 M HCl into each of five clean test tubes.
2. Place one of the tubes in an ice water bath (ice-water mix).
3. Place another in a hot water bath, maintained at about 50 degrees.
4. Place the third tube in a test tube rack at room temperature.
5. Place the fourth and fifth tubes at other temperatures between zero and 50
degrees Celsius.
6. Allow enough time for the tubes to reach the temperature of their
surroundings.
7. Clean a Zn strip with steel wool.
8. Cut five small pieces of zinc to the same size, approximately 0.5 cm x 0.5 cm.
9. Note the time and drop one piece of Zn into each of the test tubes.
10. Observe the reactions and record your observations for 2 min.
11. Test for the identity of the gas produced by holding a burning splint near the
mouth of each of the tubes.
12. Note the time each reaction ceases and any observations of the five tubes.

5. Elly Lee
December 2012– January 2013
Raw Data:
EFFECT OF TEMPERATURE ON REACTION RATE
Time
Time Reaction Reaction
Reaction Reaction Burning Splint Test
Ended Duration
Condition Started Result
( 0.5 seconds) ( 0.5 seconds)
( 0.5 seconds)
cold water
0 seconds 95 seconds 95 seconds Oxygen
6.1 0.5°C
room
temperature 0 seconds 11 seconds 11 seconds Carbon Dioxide
21.8 0.5oC
hot water
0 seconds 5 seconds 5 seconds Carbon Dioxide
49.9 0.5°C
32.3 0.5oC 0 seconds 8 seconds 8 seconds Carbon Dioxide
14.9 0.5oC 0 seconds 30 seconds 30 seconds Hydrogen
Data:
Reaction Condition Reaction Duration
Type of Gas
( 0.5°C) ( 0.5 seconds)
6.1°C 95 seconds Oxygen
21.8oC 11 seconds Carbon Dioxide
49.9°C 5 seconds Carbon Dioxide
32.3oC 8 seconds Carbon Dioxide
14.9oC 30 seconds Hydrogen

6. Elly Lee
December 2012– January 2013
Effect of Temperature on
Reaction Duration
60
50
0.5⁰C)
40
Temperature (
30
20
10
0
0 20 40 60 80 100
Reaction Duration ( 0.5 seconds)
As it is shown in the graph, the lower the temperature, the less time it takes for zinc to
react with HCl. The pieces of zinc reacted faster in HCl with higher temperature.
Observation:
In the cold water (6.1 0.5°C,) the reaction duration was about 95 seconds. The
bubbles were created when the zinc was dropped in the HCl, and it lasted for 95
seconds until the zinc completely disappeared. It slowly and constantly produced
bubbles, floated up after about 70 seconds when it was dropped in HCl, and created
bubbles without stopping, until it was completely dissolved in water after another 25
seconds. The burning splint test result showed that the gas created by this process is
oxygen, as it burned more, and fire got bigger.
In the room temperature (21.8 0.5°C), the reaction duration of the zinc was
about 11 seconds. The bubbles were produced again as soon as the zinc was dropped,
but it disappeared much more quickly than it did in the cold water. It also floated up
before it completely vanished, and it actually was gone in about 11 seconds. The
burning splint test result showed that the gas created by this process is carbon dioxide,
as the fire slowly got smaller and disappeared at last.
In the hot water (49.9 0.5°C), it took about 5 seconds until the zinc
completely disappeared in the water. In the hot water, the reaction was really fast. The
bubbles were produced for about few seconds, and the zinc just disappeared in 5
seconds. The type of gas produced after the reaction was carbon dioxide, as the fire
got smaller.

7. Elly Lee
December 2012– January 2013
In the water with temperature about 32.3 0.5°C, the reaction duration was
about 8 seconds. The bubbles were created and it floated up as well. The reaction
duration of zinc and water was faster than the one in the room temperature, but a bit
slower than the one in the hot water. The type of gas produced by the reaction was
also carbon dioxide. The fire just got smaller without any noise.
In the water with temperature about 14.9 0.5°C, the time the zinc took to
completely disappear in water was about 30 seconds. The zinc produced bubbles for
about 20 seconds and floated up after another 10 seconds. The reaction duration was
faster than the one in the cold water, but slower than the one in the room temperature
and hot water. The type of gas produced after the reaction was hydrogen. When the
burning splint was put inside the test tube, it created pop sound and the fire suddenly
disappeared.
Conclusion:
The purpose of this experiment was to observe the effects of temperature on
the rates of chemical reactions. My hypothesis was that as the temperature of the HCl
increases, the reaction rate of zinc metal gets faster. I had five test tubes at different
temperatures. I put a small piece of zinc (0.5±0.05cm∙0.5±0.05cm) in each test tube,
and recorded the reaction duration, and the type of gas produced by the reaction.
The reaction duration was shortest in the hot water (49.9±0.5℃) followed by
water with temperatures of 32.3±0.5℃, 21.8±0.5℃, 14.9±0.5℃ and 6.1±0.5℃. In
addition, the gas produced by the reaction was hydrogen, demonstrated through the
burning splint test. When I recorded the raw data, I included the starting time and the
time when the reaction ended, but in my data processing, I did not use these but rather
got the reaction duration which is the time between the starting time and the time
when the reaction actually finished. I made a graph with the data I processed with my
raw data. As it is shown in the graph, the reaction rate gets smaller as the temperature
rises.
I predicted that as the temperature of HCl increases, the reaction rate of zinc
metal gets faster. My data demonstrated that my hypothesis is correct. It was shown
that higher temperature of HCl needs less time to finish the reaction with the zinc
metal. Moreover, the result I got through this experiment demonstrate the Collision
theory, which is used to predict the rates of chemical reactions, based on the
assumption that for a reaction to occur, it is necessary for the atoms or molecules to
collide with one another. The higher temperature of HCl created more movements of
molecules in HCl which make the reaction to occur much faster. On the other hand,
the lower temperature of HCl reacted with the zinc pieces much more slowly.
Evaluation:
There was a flaw in the procedure; although I recorded the reaction duration
accurately, I made a mistake when I was doing the burning splint test. I had to put the
burning splint inside the test tube, but I did not. I rather put the burning splint above
the test tube, which gave me wrong results. As a result, I got different types of gas for

8. Elly Lee
December 2012– January 2013
test tubes at different temperatures. Other than that, no other mistakes were
recognized in this lab.
I think this mistake was avoidable. At the end of the experiment, I realized
that I did wrong with my burning splint test, by looking at what other people were
doing. I noticed that all five test tubes should have got the same type of gas, because
same reaction –reaction of HCl and the zinc pieces – happened for all five times. The
only part that should have changed was temperature and the reaction rate, not the type
of gas produced by the reaction.
If I get to do the same lab again, I would ask some questions to my
classmates or to my teacher to make sure that I understand each step of the procedure.
Also, another way I can try is to come up with a better, specific procedure so that I do
not make such mistake again. For next time, I would put the burning splint in the test
tubes, not on top of the test tubes, which would make the splint get affected by other
types of gas in the surroundings like oxygen.