Senior High School
Physical Science
Quarter 1 – Module 8:
Collision Theory
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For the learner:
Welcome to the Physical Science module on Collision Theory.
This module was created to aid you with your studies, particularly during this pandemic
when face-to-face communication is not possible. All of the materials for the activities can be
found in your homes, making them simple to complete. It is expected of you to have fun while
learning.
The following components and icons are included in this module:
What I Need to Know
This will offer you a general
overview of the skills or
competencies you should learn in
the module.
What I Know
This section offers an activity that
will test your knowledge of the
upcoming lesson. You may choose
to skip this module if you get all of
the answers correct (100%).
What’s In
This is a quick drill or refresher to
help you connect the current and
previous lessons.
What’s New
The new lesson will be introduced
to you in this section in a variety of
ways, including a narrative, a song,
a poem, a problem opener, an
activity, or a circumstance.
What is It
A brief discussion of the lesson is
provided in this section. This is
designed to assist you in learning
new concepts and skills.
What’s More
This section contains tasks for
individual practice to help you
solidify your knowledge and
abilities on the subject.
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What I Have Learned
This may include fill-in-the-blank
questions or blank
sentences/paragraphs to help you
absorb what you learned in the
class.
What I Can Do
This section has an activity that will
assist you in applying your new
knowledge or skill to real-world
problems or issues.
Assessment
This task is designed to assess your
mastery of the learning
competency.
Additional Activities
Another activity will be offered to
you in this section to help you
expand your knowledge or skill of
the lesson you just studied.
Answer Key
This contains answers to all
activities in the module.
At the end of this module you will also find:
References
This is a list of all sources used
in developing this module.
The following are some reminders in using this module:
1. Use the module with care.
2. Don’t forget to answer “What I Know” before moving on to the other activities included in
the module.
3. Read the instruction carefully before doing each task.
4. Observe honesty and integrity in doing the tasks and checking your answers.
5. Finish the task at hand before proceeding to the next.
6. If you encounter difficulty in answering this module, do not hesitate to ask your teacher.
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What I Need to Know
This module is created and written is to assist learners in recognizing how Collision
Theory affects the chemical reaction rate. Collision theory explains chemical reactions and
their rates in a qualitative manner. The key principle of collision theory is that molecules must
collide to react. This basic rule guides any analysis of an ordinary mechanism of reaction.
The scope of this learning material covers many different learning situations where
learners could relate their personal experiences. The language used recognizes the diverse
vocabulary level of learners. The lessons are organized following the regular order of the
course.
Learning Competency:
•
The learners:
use simple collision theory to explain the effects of concentration, temperature, and
particle size on the rate of reaction S11/12PS-IIIf-23
Specifically, the lesson objectives are:
1. describe collision theory;
2. explain the effects of concentration, temperature, and particle size on the rate of
reaction; and
3. relate collision theory with everyday life experience.
What I Know
Direction: Read each statement carefully. Choose the letter of the best answer. Write the
chosen letter on a separate sheet of paper.
1. What is collision theory?
a. Molecules must collide in the correct orientation with enough energy to bond.
b. Molecules need enough energy to collide and react.
c. Atoms constantly collide and react.
d. The minimum energy needed for atoms to react.
2. What is the rate of reaction?
a. How much energy is needed for a reaction to occur.
b. The energy required to break a bond.
c. The time it takes for a reaction to occur.
d. Collision Theory
3. What factors affect the rate of reaction?
a. Temperature, Concentration, Pressure, and Energy
b. Surface Area, Concentration, Energy, and Pressure
c. Temperature, Catalyst, Concentration, and Surface area
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d. Pressure, Surface area, Density and Energy
4. Increasing the temperature of your solution will _____.
a. not affect the rate of reaction.
b. speeds up the rate of reaction.
c. slows down the rate of reaction.
d. either speeds up or slows down the rate of reaction.
5. Decreasing the concentration of a substance will _______.
a. slows down the reaction.
b. speeds up the reaction.
c. does not affect the reaction.
d. either speeds up or slows down the rate of reaction.
6. Which has more surface area?
a. large chunks of chalk
b. cube of sugar
c. powdered sugar
d. small chunks of sugar
7. If you shrink the container size that your gas substance is in, what will happen?
a. The reaction rate will stay the same
b. The reaction rate will speed up
c. The reaction rate will slow down
d. either speed up or slow down the rate of reaction
8. More collisions correspond to a:
a. faster reaction rate
b. slower reaction rate
c. constant reaction rate
d. none of the above
9. What criteria must be met for reactant collisions to result in a successful product?
a. The reactants must collide with each other
b. The reactants must collide with enough energy and be in the right positions
c. The reactants must have enough energy to form the activated complex
d. none of the above
10. What is a catalyst?
a. Something added to a reaction to slow it down
b. Something added to a reaction to speed it up
c. Something added to a reaction to increase the surface area
d. Something added to a reaction to change its concentration
11. Which is/are factor/s that would affect the rate of a reaction?
a. temperature
b. adding a catalyst
c. concentration
d. all of the choices
12. If I wanted to create more space for particles to collide, I would ____.
a. raise the pressure
b. raise the temperature
c. increase the concentration
d. increase the surface area
13. Which of the following would NOT increase the rate of reaction?
a. increasing the temperature
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b. increasing the surface area
c. increasing the volume
d. increasing the concentrations
14. As the temperature of a reaction is increased, the rate of the reaction increases because
the __________.
a. reactant molecules collide less frequently
b. reactant molecules collide more frequently and with greater energy per collision
c. activation energy is lowered
d. reactant molecules collide less frequently and with greater energy per collision
15. The rate of a reaction depends on __________.
a. collision frequency
c. collision orientation
b. collision energy
d. all of the choices
What’s In
We encounter chemical reactions everywhere. A substance changes in the presence
of another substance or even by itself. Because there are tens of millions of known
substances, there are a huge number of possible chemical reactions. We see them every day
like combustion, photosynthesis, aerobic cellular respiration, anaerobic respiration (including
fermentation), oxidation (including rust), digestion, and many more. A chemical reaction is a
process in which one or more substances, also called reactants, are converted to one or more
different substances, known as products. Chemical reactions occur at various speeds.
Reactions might happen quite quickly like striking a match and burning of petrol in the car
engine, or slowly like for example rusting of iron or fermentation of sugar into ethyl alcohol and
carbon dioxide can take place in several hours or even in several days. Have you ever
wondered why a chemical reaction happens? What elements are required for a chemical
reaction to take place?
In this lesson, learners will describe collision theory, which is used to predict the rates
of chemical reactions. Learners will determine the different factors that affect the rate of
reaction.
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What’s New
Activity 1. Reaction Rates: When Surface Area Matters!
I. Objective: To investigate the effect of particle size on the rate of a reaction.
II. Materials:
vinegar – 100 mL
chalk – 2 small pieces (same size)
2 similar cups
a mortar and pestle
stopwatch
III. Procedure:
1. Grind 1 piece of chalk using a mortar and pestle (put the powdered chalk in a
cup)
2. Leave the 2nd piece of chalk whole (put the chalk in a cup)
3. Prepare a stopwatch to time the reactions.
4. Add 100 mL of vinegar to the ground chalk.
5. Observe the reaction and record observations.
6. Time the reaction and record.
7. Add 100 mL to the entire piece of chalk
8. Observe the reaction and record observations
9. Time the reaction and record your observations in Table 1.
IV. Results:
Table 1: The Effect of Surface Area/ Particle Size on Reaction Rates
Material
Time the tablet was fully
Observations
dissolved
Whole chalk
Powdered chalk
Guide Questions:
1. Which piece of chalk produced a faster reaction? Why?
_________________________________________________________________
___________________________________________________________
3. Explain the effects of particle size on the rate of reaction.
_________________________________________________________________
_______________________________________________________________
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V. Conclusion:
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Activity 2. The Effect of Concentration on Reaction Rates
I. Objective: Investigate the effect of concentration on the rate of a reaction.
II. Materials:
3 clear drinking glasses
baking soda
vinegar
spoon
III. Procedure:
1. Prepare 3 drinking glasses.
1. Dilute vinegar in water to get three different concentrations. The ratio of water to
vinegar 0:1 (pure vinegar), 1:1, and 2:1. (make sure to have a total of 100 ml for
each solution.
2. Quickly add 1 tbsp. of baking soda to each concentration and stir. Note the
difference in reactions.
3. Record your observations.
IV. Results:
Table 2: The Effect of Concentration on Reaction Rates
Materials
Observations
Vinegar 0:1
Vinegar 1:1
Vinegar 2:1
Guide Questions:
1. Which glass has the most amount of bubbles formed? Why?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
3. Explain the effects of concentration on the rate of reaction.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
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V. Conclusion:
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Activity 3: The Effect of Temperature on Reaction Rates
I. Objective: Investigate the effect of temperature on the rate of a reaction.
II. Materials:
3 clear drinking glasses
brown sugar
spoon
hot water
tap water (room temperature)
cold water
ice (optional)
III. Procedure:
1. Prepare 3 drinking glasses
2. Fill the first glass with 100 ml hot water, fill the second glass with 100 ml tap
water, and fill the third glass with 100 ml cold water (you may add ice if you like).
3. In each glass, put 1 tbsp. of brown sugar.
4. Stir each glass 10 times using the spoon.
5. Observe what happen to the sugar at the bottom of each glass.
6. Record your observations in Table 3.
IV. Results:
Table 3. The Effect of Temperature on Reaction Rates
Materials
Observations
hot water
tap water
cold water
Guide Questions:
1. Which glass has the least amount of sugar at the bottom of the glass? Why?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
3. Explain the effects of temperature on the rate of reaction.
_________________________________________________________________
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_________________________________________________________________
_________________________________________________________________
V. Conclusion:
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
Activity 4: The Effect of Catalyst on Reaction Rates
I. Objective: Investigate the effect of catalyst on the rate of a reaction.
II. Materials:
2 clear drinking glasses
hydrogen peroxide
spoon
yeast
III. Procedure:
1. Prepare 2 clear drinking glasses
2. Fill each glass with 25 ml Hydrogen peroxide.
3. Put ½ tsp of yeast in the first glass, then just let the second glass be as it is.
4. Observe which glass will produce more bubbles.
6. Record your observations.
IV. Results:
Table 4. The Effect of Catalyst on Reaction Rates
Materials
Hydrogen peroxide
Hydrogen peroxide with yeast
Observations
Guide Questions:
1. Which glass has produced more bubbles? Why?
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
3. Explain the effects of catalyst on the rate of reaction.
_________________________________________________________________
_________________________________________________________________
_________________________________________________________________
V. Conclusion:
_________________________________________________________________
_________________________________________________________________
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_________________________________________________________________
_________________________________________________________________
What is It
Collision Theory: How Chemical Reactions Occur
Collision theory states that for a chemical reaction to take place, the reacting
particles must collide. The rate of the reaction depends on the frequency of collisions.
The theory also tells us that reacting particles often collide without reacting. The kinetic
energy required to break the necessary bonds and make new bonds is provided by
the collision of molecules in a chemical process. Even when there is a collision, not all
collisions are successful. For collisions to be effective collisions, particles must
possess the minimum amount of energy needed for the reaction and must collide with
proper orientation. This energy, used to initiate the reaction, is called the activation
energy. The activation energy of a chemical reaction is closely related to its rate.
Specifically, the higher the activation energy, the slower the chemical reaction will be.
This is because molecules can only complete the reaction once they have reached the
top of the activation energy barrier.
Factors that Affect Reaction Rates
The collision theory is used to explain the factors that affect the reaction rate.
The four main factors that affect reaction rate are particle size (surface area) of the
reactants, the concentration of the reactants, temperature, and the presence of
catalysts. Let us explore these factors that affect the reaction rate.
Effect of Surface Area on Reaction Rate:
In Activity 1, we used whole chalk and powdered chalk to compare the rates of
reaction. You observed that the powdered chalk dissolves faster in a cup of water
than the whole chalk. This happened because while they have the same mass, they
differ in surface area. Breaking the chalk into smaller pieces increases its surface area
allowing more particles to be available for a collision. In collision theory, the solid is
divided into smaller pieces, then there is a greater surface area; therefore, more
particles can react, and the reaction rate increases.
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Figure 1: Surface area of solid
Any reaction involving a solid can only occur at the solid's surface. The surface area
of solid increases as it is divided into several pieces. This means that the reactant
particles will collide with a larger surface area. The smaller the pieces, the larger the
surface area. This suggests that there will be more collisions and a higher possibility
of a reaction.
Remember!
If the surface area of a reactant is increased:
•
more particles are exposed to the other reactant
•
there are more collisions
•
the rate of reaction increases
Effect of Concentration on Reaction Rate:
In Activity 2, we used 3 concentrations of vinegar were used. Pure vinegar has
the most produced bubbles while the least concentrated vinegar has the least
produced bubbles.
Figure 2: Concentration of molecules
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An increase in the concentration of reactants increases the reaction rate. At
higher concentrations, the molecules of the reactants are closer to each other;
therefore, collisions occur more frequently, a higher percentage of collisions are
effective, and the reaction rate increases.
Remember!
•
•
•
increasing the concentration of a reactant, there will be more of the chemical
present.
more reactant particles moving together allow more collisions to happen, so the
reaction rate is increased.
the higher the concentration of reactants, the faster the rate of a reaction will
be.
Effect of Temperature on Reaction Rate:
In Activity 3, we filled 3 drinking glasses with 3 different temperatures of water
then added an equal amount of brown sugar to each glass. We observed that an
increase in the temperature of reactants usually increases the reaction rate. At higher
temperatures, the molecules of the reactants move faster; therefore, collisions occur
more frequently, a higher percentage of collisions are effective, and the reaction rate
increases. A general rule of thumb is that on average, the reaction rate doubles for
every 10°C rise in temperature.
Remember!
•
•
•
Reactants must be moving fast enough and hit each other hard enough for a
chemical reaction to take place.
Increasing the temperature increases the average speed of the reactant
molecules.
As more molecules move faster, the number of molecules moving fast enough
to react increases, which results in the faster formation of products.
Effect of a Catalyst on Reaction Rate:
In Activity 4, we prepared 2 glasses with 25 ml of hydrogen peroxide. Then we
added ½ tsp. to 1 glass then let the other glass stay as it is. We observed that more
bubbles were produced with the presence of yeast. This is because the yeast acts as
a catalyst for the decomposition of hydrogen peroxide into hydrogen gas and oxygen
gas.
A catalyst is a substance that changes the reaction rate without being consumed
by the reaction. A catalyst acts by lowering the activation energy required for a reaction
to take place, thus allowing the reaction to occur more rapidly. (This will be discussed
more in the next module).
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What’s More
Activity 5. Increase-Decrease!
Complete the following table by indicating whether each of the following scenarios
would either increase or decrease the rate of reaction.
Scenario
Effect on Chemical Reaction Rate
removing heat
diluting a solution
decreasing surface area
adding a catalyst
increasing temperature
Activity 6. What is it!
Direction: Complete the table by indicating which factor would have the greatest
impact on the rate of reaction of these real-life situations.
Scenario
Factors that Effect
Chemical Reaction Rate
1. cooking small slices of meat
2. exhaust from car engine passes through a
converter changing poisonous nitrogen oxides into
nitrogen gas and oxygen gas
3. storing milk in the refrigerator
4. salt dissolves fast in hot water
5. Tearing paper into small pieces
6. leaving fresh fish on top of a table
7. fruits and vegetables ripen faster in the summer
than during rainy days
8. two antacid tablets will neutralize a given amount
of acid faster than one tablet will
9. smaller pieces of charcoal are used to cook food
faster
10. industries break down pulp to produce sanitary
paper
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What I Have Learned
Sentence Completion. Complete each statement with a word/ concept in the blank of the
item.
1. A freshly exposed surface of metallic sodium tarnishes almost instantly if exposed to air and
moisture, while iron will slowly turn to rust under the same conditions. In these two situations,
the__________________ refers to how quickly or slowly reactants turn into products.
2. Adding _________________________ will increase the rate of reaction because this
causes the particles of the reactants to move more quickly, resulting in more collisions and
more ______________________.
3. Removing heat will lower the ____________________, causing the particles of the
reactants to slow
down, resulting in less frequent collisions.
4. ___________________ refers to how much solute is dissolved in a solution. If there is a
greater concentration of reactant particles present, there is a greater chance that
__________________ among them will occur. More collisions mean a higher rate of reaction.
5. A concentrated acid solution will react more quickly than a _______________ acid solution
because there are more molecules present, increasing the chance of collisions.
6. Grains of sugar have a greater ______________________ than a solid cube of sugar of
the same mass, and therefore will dissolve quicker in water.
7. A ______________ therefore speeds up a reaction but remains unchanged after the
reaction is complete.
8. _____________________ states that for a chemical reaction to occur, the reacting
particles must collide with one another.
9. If a reaction has a low rate, that means the molecules combine at a _________speed than
a reaction with a high rate.
10. A chemical reaction between two or more substances requires close _________ between
the reactants.
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What I Can Do
YOU GOT THIS!
Direction: Choose from one of the factors that affect the rate of chemical reaction (surface
area, temperature, concentration, and catalyst). Give a real-life example of what you have
chosen. Explain why it can affect the rate of reaction. Then take a photo of your example and
attach it below.
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
Assessment
Direction: Read each statement carefully. Choose the letter of the best answer. Write the
chosen letter on a separate sheet of paper.
1. What factors affect the rate of reaction?
a. Temperature, Concentration, Pressure, and Energy
b. Surface Area, Concentration, Energy, and Pressure
c. Temperature, Catalyst, Concentration, and Surface area
d. Pressure, Surface area, Density and Energy
2. Increasing the temperature of your solution will _____.
a. not affect the rate of reaction.
b. speed up the rate of reaction.
c. slows down the rate of reaction.
d. either speeds up or slows down the rate of reaction.
3. Which has more surface area?
a. large chunks of chalk
b. cube of sugar
c. powdered sugar
d. small chunks of sugar
4. As the temperature of a reaction is increased, the rate of the reaction increases because
the __________.
a. reactant molecules collide less frequently
b. reactant molecules collide more frequently and with greater energy per collision
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c. activation energy is lowered
d. reactant molecules collide less frequently and with greater energy per collision
5. If you shrink the container size that your gas substance is in what will happen?
a. The reaction rate will stay the same
b. The reaction rate will speed up
c. The reaction rate will slow down
d. either speed up or slow down the rate of reaction
6. What is collision theory?
a. Molecules must collide in the correct orientation with enough energy to bond.
b. Molecules need enough energy to collide and react.
c. Atoms constantly collide and react.
d. The minimum energy needed for atoms to react.
7. More collisions correspond to a:
a. faster reaction rate
b. slower reaction rate
c. constant reaction rate
d. none of the above
8. What is a catalyst?
a. Something added to a reaction to slow it down
b. Something added to a reaction to speed it up
c. Something added to a reaction to increase the surface area
d. Something added to a reaction to change its concentration
9. Decreasing the concentration of a substance will _______.
a. slows down the reaction.
b. speeds up the reaction.
c. has no effect on the reaction.
d. either speeds up or slows down the rate of reaction.
10. Which is/are factor/s that would affect the rate of a reaction?
a. temperature
b. adding a catalyst
c. concentration
d. all of the choices
11. What is the rate of reaction?
a. How much energy is needed for a reaction to occur.
b. The energy required to break a bond.
c. The time it takes for a reaction to occur.
d. Collision Theory
12. Which of the following would NOT increase the rate of reaction?
a. increasing the temperature
b. increasing the surface area
c. increasing the volume
d. increasing the concentrations
13. The rate of a reaction depends on __________.
a. collision frequency
c. collision orientation
b. collision energy
d. all of the choices
14. If I wanted to create more space for particles to collide, I would ____.
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a. add catalyst
b. raise the temperature
c. increase the concentration
d. increase the surface area
15. What criteria must be met for reactant collisions to result in a successful product?
a. The reactants must collide with each other
b. The reactants must collide with enough energy and be in the right positions
c. The reactants must have enough energy to form the activated complex
d. none of the above
WORD MATCH!
Direction: Draw a line from each word in column A to its description in column B.
A
1. catalyst
2. concentration
3. surface area
4. temperature
5. collision theory
B
a. It is the measure of how much of a given substance there is
mixed with another substance.
b. It is the degree or intensity of heat present in a substance or
object.
c. For a collision to be successful, reacting particles must collide
with sufficient energy, and with the proper orientation.
d. It is a measure of the total area that the surface of the object
occupies.
e. It is a substance that increases the rate of a chemical reaction
without itself undergoing any chemical change.
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Answer Key
REFERENCES
Reyes, J. A. C., & Reyes, M. A. C. (2017). Physical Science. JIMCZYVILLE Publications.
Sabibio, M. B., & David, O. M. (2019). Physical Science (2nd ed.). DIWA Learning Systems
Inc.
Ungson, O. B., & Teofe, F. T. (2016). Physical Science. Trinitas Publishing Inc.
Wilson, J. D., Higgins Jr., C. A., & Torres, O. (2016). An Introduction to Physical Science
(14th ed.). Rex Book Store Inc.
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