Republic of the Philippines
Department of Education
Regional Office IX, Zamboanga
Peninsula
10
Z
est for
P
rogress
Z P
eal of
Science Grade 10
Quarter 4 - Module 7
Collision Theory and the
Factors Affecting the Rates
of Chemical Reactions:
Catalyst and Temperature
Name of Learner: __________________________________
Grade & Section: __________________________________
Name of School: ___________________________________
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artnrship
Module
Collision Theory and the
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Factors Affecting the Rates of
Chemical Reactions: Catalyst
and Temperature
What I Need to Know
This module is prepared to facilitate your understanding and
learning of some of the essential concepts and explain how the
factors affecting rates of chemical reactions are applied in food
preservation and materials production, control of fire, pollution, and
corrosion (S10MT-IVh-j-24). The primary goal of this module is to
engage you in simple interactive activities to explore concepts related
to chemical reaction and how it is being applied to real-life situations.
After going through this module, you are expected to:
1. Describe Collision Theory;
2. Discuss how temperature and catalyst affect the rate of chemical
reactions;
3. Explain how temperature and catalyst are applied in food
preservation and materials production, control of fire, pollution,
and corrosion
Among the questions, most people ask about the daily
occurrences in life: Why does raising the temperature shorten the
cooking time? Why does a log of wood take a longer time to burn
than small pieces of wood? Why do fruits ripen when kept in a warm
place? Why does a baker put yeast in baking? How does yeast help
in fermentation, specifically in winemaking?
What does a chemical reaction rate tell you? It tells you how
fast the reaction takes place. What factors cause chemical reaction
rates? Factors that affect the chemical reaction rate include
temperature and catalyst.
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What’s In
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Activity 1A: When Collision Takes Place
Direction: Complete the table by indicating whether each of the scenarios
would increase or decrease the rate of chemical reaction.
Scenario
Increase or Decrease
1. Increasing the temperature
2. Decreasing the temperature
3. Adding an enzyme/ catalyst
4. Decreasing the enzyme/ catalyst
5. Lower the activation energy
Activity IB.
Direction. Complete the table by indicating what factor would have the
most significant impact on a chemical reaction rate. Write the word catalyst
and temperature.
Scenario
Factor that has a great
impact on the rate of
chemical reaction
1. Carbohydrates are broken down
in the small intestine by the
enzymes sucrase and lactase.
2. Increasing the temperature while
cooking.
3. Blowing air on fire to help it keep
going.
4. In a polluted atmosphere where
sulfur dioxide concentration is high,
calcium carbonates deteriorate more
rapidly than in less polluted air.
5. Putting food inside the
refrigerator to prevent it from
spoiling.
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What’s New
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These simple science activities describe how collision theory takes place
and demonstrate how catalyst and temperature affect
the rate of
chemical reaction.
Activity 2A: When Particles Collide..
Task: Analysis of molecular representation of collision theory
Source: http://wps.prenhall.com/wps/media/objects/3082/3156859/blb1404/bl14fg16.jpg
accessed: Oct.29, 2014
Source: http://i.ytimg.com/vi/OkGzaSOkyf4/maxresdefault.jpg (accessed: Oct.29, 2014)
The
illustrations above show the effective and ineffective collision of molecules
to effect a chemical reaction.
Guide Questions:
1. What causes a chemical reaction? ( 1pt.)
_____________________________________________________________
_____________________________________________________________
_______________________________________________________
2. What must happen for a chemical reaction to take place? (2 pts.)
___________________________________________________
___________________________________________________
___________________________________________________
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3. Describe an effective chemical reaction resulting to a formation of
products. (2 pts.)
_________________________________________________________
_________________________________________________________
_________________________________________________________
Activity 2B: Relax, Have a Coffee Break
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Materials Needed:
2 Sachets Coffee powder
2 Cups
Coldwater
Hot water
2 tsp sugar
2 tsp of milk
Hot Coffee
Cold Coffee
Procedure:
1. Pour the coffee into the cups. (Hot water for Cup A and Cold
Water for Cup B). Pour 1 tsp of sugar and milk in each cup
2. Stir the contents of Cup A and do not stir the contents of Cup B
3. Taste the mixture in each cup.
Guide Questions:
1. Which coffee mixture tastes better? Why? (2 pts.)
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
2. Does temperature affects the taste of the mixture? Why? (2 pts)
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________
3. Does stirring affect the taste of the mixture? Why? (2 pts)
___________________________________________________________
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___________________________________________________________
___________________________________________________________
___________________________________________________________
___________________________________________________________ Activity 2C.
Let’s Make Some Bubbles!
Materials Needed:
Transparent Glass
•
•
3% Hydrogen Peroxide ( Agua Oxinada)
Detergent solution
(Mix 1tsp of detergent powder/liquid to 2 tsp. of water)
•
•
•
Yeast
Dropper
Popsicle stick
Procedure:
1. Add 10 ml of hydrogen peroxide to a transparent glass. Add 1
drop of detergent solution. Stir gently and watch the solution
for bubbling.
2. Use the end of the Popsicle stick to add a small amount of
yeast to the hydrogen peroxide. Stir the solution.
3. Observe the solution.
Guide Questions:
1. What will happen to the hydrogen peroxide if you add the yeast to
it? (2 pts)
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
2. What is the catalyst in the activity? (2 pts)
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
______________________________________________________________
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What is it
COLLISION THEORY
Collision theory explains how the collision between reactant
molecules may or may not result in a successful chemical
reaction. There must be an effective collision of particles for a
chemical reaction to take place. Based on this theory, not all
collisions between the molecules result in the formation of
products. Effective collisions between molecules, which result
in the formation of products, only occur when the following two
conditions are met:
(a)
the colliding molecules should possess minimum
kinetic energy, known as activation energy, to start a
chemical reaction.
(b)
the reactant molecules should be in the correct
orientation when they collide
In 1888 Svante Arrhenius suggested that particles must
possess. A certain minimum amount of kinetic energy to react.
The energy diagram is shown below.
Energy diagrams are used to analyze the energy changes
that occur during a chemical reaction. The energy of the
reactants must be raised over an energy barrier.
Activation energy is the energy required to initiate a reaction and force the
reactants to form an activated complex.
The activated complex is located at the peak of the energy
diagram for a reaction.
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Catalysts
It is a substance that can be added to a reaction to increase the
reaction rate without getting consumed in the process. Enzymes are
proteins that act as catalysts in biochemical reactions. The very
common examples for this are the Photosynthesis and Cellular
Respiration. Biological systems use catalysts to increase the rate of
the oxidation reaction so that it can occur at a faster rate at lower
temperatures. Catalysts are everywhere! Many biochemical processes,
such as the oxidation of glucose, are heavily dependent on enzymes,
proteins that behave as catalysts.
Catalysts increase the rates of chemical
reactions. This is due to
lowering of the activation energy for the
reaction. Catalysts are not consumed in
the reaction so in theory, they can be
used
over and over again. In practice, they are often contaminated and/or
some is lost in a process.
Temperature
Chemical reactions typically occur faster at higher temperatures. Food
can spoil quickly when left on the kitchen counter. However, the lower
temperature inside of a refrigerator slows that process so that the same
food remains fresh for days.
The higher the temperature, the higher the rate of reaction. At higher
temperature, atoms have higher kinetic energy,
making the particles move faster and therefore increase the chance
for the particles to come in contact with each other. Key point: at a
higher temperature more molecules have energy greater than the
activation energy.
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This is also the reason why most fruits and vegetables ripen in the
summer when the temperature is much warmer. When a banana ripens,
numerous reactions occur that produce all the compounds that we expect
to taste in a banana. But this can only happen if the temperature is high
enough to allow these reactions to make those products.
Food storage is a prime example of how the temperature
effect on reaction rate is utilized by society. Consumers store food
in freezers and refrigerators to slow down the processes that cause
it to spoil. The decrease in temperature decreases the rate at which
food will break down or be broken down by bacteria.
What’s More
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Activity 3: Tell Me What
Directions: Tell whether the following images are related to temperature
or catalyst.(5 pts.)
Refrigeration
1. ___________________________
2. _________________________
Pollution
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3. _______________________________
Photosynthesis
Yeast
4. _______________________________
______________________________
5.
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What I Have Learned
Activity 4: Let’s see what you have learned!
Directions: Complete the statements by underlining the appropriate word or
phrase.
(2pts each.)
1.
For the reaction to occur, reacting particles must (collide, move) and
this collision must be effective.
2.
(Activation Energy, Enough Energy) is the energy required to
initiate a reaction and force the particles to form an activated complex. 3.
The (higher, lower) the temperature, the higher the rate of chemical
reaction.
4.
(Catalysts, Energy) increase the rates of chemical reactions.
This is due to lower of the activation energy for the reaction.
5.
(Enzyme, Lipids) are proteins that act as a catalyst in biochemical
reactions.
You did it! Keep up the good work. This would help you
understand the factors that affect the chemical reaction.
There’s more that you can do.
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What I Can Do
Activity 5: You can do great
Directions: A. Choose from the words on the box that will make the statement
complete.
( 2 pts. each)
-collide
-Chemical Reaction
-effective
- Activation Energy
- products
Collision theory explains how the collision between reactant molecules
may or may not result in a successful
___________________.There must be an __________________________ collision
of particles for a chemical reaction to take place. Based on this theory, not
all collisions between the molecules result in the formation of
__________________. Effective collisions between molecules, which result in
the formation of products, only occur when the following two conditions
are met in which the colliding molecules should possess minimum kinetic
energy, known as ______________________, to start a chemical reaction. (b)
the reactant molecules should be in the correct orientation when they
______________________________.
B. Directions: Study the pictures below. Identify the factor that affects
the rate of the chemical reaction. Write catalyst or temperature.
1.
2.
Cooking Meat
Decomposition
_______________________________
____________________________
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3.
4.
Air Pollution
Corrosion
______________________________
_____________________________
5.
Catalytic Converter
________________________________
Post Assessment (Set A)
Directions. Encircle the letter of the best answer.
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1. It refers to the minimum energy required for reactions to start.
A. Activation energy
C. Potential energy
B. Kinetic energy
D. Stored energy
2. Which of the following is not a factor that affects the reaction rates?
A. Reactant concentration
C. Particle size
B. Catalysts
D. Shape of particles
3. What is the name of the theory which is used to explain how different
factors affect the rate of a reaction?
A. Big bang Theory
C. Continental Theory
B. Collision Theory
D. Particle Theory
4. Which of the following would speed up a chemical reaction?
A. Adding some water
C. Increasing the temperature
B. Decreasing the temperature D. Increasing the volume
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5. What criteria must be met for reactant collisions to result in a
successful product formation?
A. Activated complex and energy
C. Collision, enough energy
B. Collision of the reactants
D. All of these
6. What does a temperature do to the reactants during a chemical reaction?
A. It increases the volume of reactants
C. It makes the
reactants big
B. It increases the average speed of the reactant D. All of these 7. Why
does increasing the temperature of the reactants increase the rate
of a chemical reaction?
A. Heat energy causes the particles of the reactants to move faster,
and
therefore react with each other more frequently
B. Heat energy causes some of the reactants to evaporate, increasing
the
concentration of the reactants
C. Heat energy increases the size of the molecules of reactants, and
therefore the molecules react more frequently
D. Heat energy helps to lower the amount of overall energy that is
required
for the reaction to occur
8. Why do foods stored in refrigerators?
A. Bacteria do not grow well in dark places
B. Refrigerators often contain enzymes that slow the rate of food
spoiling C. The lower temperatures cause the chemical reactions
that spoil food to
occur more slowly than usual
D. The volume inside the refrigerator decreases the concentration of the
food particles, allowing them to decompose more slowly
9. Enzymes are an important component of the human body. It can affect
the
rate of a chemical reaction. What are enzymes?
A. Catalysts
C. Molecules
B. Dust particles
D. Simple Elements
10.
Which of the following situations in which temperature and catalysts
are applied?
A. Baking
C. Decomposition
B. Corrosion of metals
D. All of these
Assessment (Set B)
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Directions: Encircle the letter of the best answer.
1. What is required for a chemical reaction to occur?
A. Collision
C. Energy
B. Collision with sufficient energy D. Temperature
2. Which of the following will lower the activation energy of a reaction?
A. Adding a catalyst
C. Removing a catalyst
B. Increasing the temperature
D. None of these
3. Which of the following would NOT increase the rate of reaction?
A. Adding catalyst
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B. Increasing the concentration of the reactants
C. Increasing the volume of the container
D. None of these
4. Which of the following statements about collision is correct?
A. All colliding particles have the same amount of energy
B. Only fast-moving particles collide with each other
C. Reactions can happen if the colliding particles have enough energy D.
Reaction will occur even without collision of particles
5. Why do fruits easily ripen during the summer season?
A. Heat lowers the activation energy of the reactants
B. High temperature increases the rate of a chemical reaction
C. Molecules are heavy during the summer season
D. All of these
6. What does incomplete combustion do on the car engine?
A. It provides fuel to the engine
C. Produces Oxygen
B. It Pumps fuel
D. Produces Carbon Monoxide 7. What
will you do to prevent/ control fires?
A. Don’t refuel gasoline-powered equipment while it is hot
B. Keep flammable liquids stored in a tightly closed container
C. Use flammable liquids in a well- ventilated areas
D. All of these
8. What does a catalyst do in a chemical reaction?
A.
Cools down the reaction
C. Increases the rate of the reaction
B.
Increases the concentration D. Stabilizes the chemical reaction 9.
Enzymes are catalysts that hasten the chemical reaction. Which of the
following processes involved enzymes?
A. Cellular respiration
C. Photosynthesis
B. Decomposition
D. All of these
10. Which of the following is/are considered as polluters come from the
burning of fuel?
A. Coal
C. Oil
B. Natural gas
D. All of these
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Additional Activities
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Activity 6: Let’s add more!
Direction: TRUE or FALSE. Write TRUE if the statement is correct.
If it is incorrect, write false and underline the incorrect word.
___________ 1. Effective collision results to product formation.
___________ 2. Effective collision is defined as one in which molecules collide
with sufficient energy and proper orientation.
___________ 3. Collision between reactant molecules may or may not result
in successful chemical reaction.
___________ 4. All collisions between molecules result in the formation of
products.
___________ 5. The only condition needed for effective collision is the correct
orientation of the reactant molecules when they collide.
___________ 6. Activation energy is needed to break the bond between
reactant molecules to form new bonds leading to the
formation of the products.
___________ 7. Molecules must collide with sufficient energy even with no
proper orientation in order for a chemical reaction to occur.
___________ 8. When the temperature of the reactants is increased it will
lead to higher activation energy.
___________ 9. Flame is a source of activation energy so firecrackers must
be kept/stored in cool dry place to prevent unexpected
explosion.
___________ 10. The “No Smoking” signs in gasoline station is irrelevant
because gasoline is not combustible.
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Answer Key- Gr10-Q4W7 Science
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