Transcript Collision Theory

Kinetics
Lesson 3
Collision Theory
The Collision Theory
Link to Simulation of Molecular Motion
1.
2.
3.
4.
5.
6.
Matter consists of moving particles.
As the temperature increases the particles move
faster and collide more often and with more energy.
In chemical reactions bonds must be broken and
new ones formed.
The energy for this comes from particle collisions.
The collisions have a variety of energy, as some are
harder than others.
A collision energy diagram is a graph of the number
of the collisions versus the energy of each collision.
Collision Energy Diagram Simulation
100 %
Percent
of
Collisions
With
Energy
0%
Low
Collision energy
High
Collision Energy Diagram
100 %
Activation Energy Ea- minimum energy required
for a successful collision- to break the bonds!
Percent
of
Collisions
With
Energy
0%
Low
Collision energy
High
Collision Energy Diagram
100 %
Activation Energy Ea- minimum energy required
for a successful collision- too break the bonds!
Percent
of
Collisions
With
Energy
0%
Low
Collision energy
High
Collision Energy Diagram
100 %
Activation Energy Ea- minimum energy required
for a successful collision- too break the bonds!
Percent
of
Collisions
With
Energy
This area represents the
fraction of collisions
that do not have the Eanot successful.
0%
Low
Collision energy
High
Collision Energy Diagram
100 %
Activation Energy Ea- minimum energy required
for a successful collision- too break the bonds!
Percent
of
Collisions
With
Energy
This area represents the
fraction of collisions
with the Ea -successful.
0%
Low
Collision energy
High
What happens to the number of successful collisions if
we add a catalyst, which lowers the activation energy
Ea?
Watch!
Collision Energy Diagram
100 %
Activation Energy Ea- minimum energy required
for a successful collision- too break the bonds!
Percent
of
Collisions
With
Energy
This area represents the
fraction of collisions
with the Ea -successful
0%
Low
Collision energy
High
Collision Energy Diagram
100 %
Activation Energy Ea- minimum energy required
for a successful collision- too break the bonds!
Lowering the Ea
increases successful
collisions!
Percent
of
Collisions
With
Energy
0%
Low
Collision energy
High
What happens to the number of successful collisions if
we increase the temperature- so that the average
collision energy is greater?
Watch!
Collision Energy Diagram
100 %
Activation Energy Ea- minimum energy required
for a successful collision- too break the bonds!
Percent
of
Collisions
With
Energy
0%
Low
Collision energy
High
Collision Energy Diagram
100 %
Percent
of
Collisions
With
Energy
Activation Energy Ea- minimum energy required
for a successful collision- too break the bonds!
Push the graph
down and right!
Increasing the temperature
increases successful
collisions- increases rate!
0%
Low
Collision energy
High
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry
products
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry versus Poor Geometry
products
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry versus Poor Geometry
products
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry versus Poor Geometry
products
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry versus Poor Geometry
products
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry versus Poor Geometry
products
no products
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
1.
Favourable Geometry versus Poor Geometry
products
no products
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2.
Sufficient Energy to break the chemical bonds
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2.
Sufficient Energy to break the chemical bonds
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2.
Sufficient Energy to break the chemical bonds
Collision Theory
You need a collision to have a reaction.
Collisions provide the energy required to break bonds.
Most collisions are not successful
A successful collision requires:
2.
Sufficient Energy to break the chemical bonds
Activation energy is the minimum amount of energy
required for a successful collision.
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
Reaction rates can increase due to
1.
More collisions
2.
Harder collisions- greater collision energy
3.
Lower activation energy or Ea, which allows low
energy collisions to be more effective.
And that’s it!
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
1.
Increasing the temperature increases the rate
because there are:
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
1.
Increasing the temperature increases the rate
because there are:
More frequent collisions
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
1.
Increasing the temperature increases the rate
because there are:
More frequent collisions
Harder collisions
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
2.
Increasing the reactant concentration increases the
rate because there are:
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
2.
Increasing the reactant concentration increases the
rate because there are:
More frequent collisions
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
3.
Adding a catalyst increases the rate because:
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
3.
Adding a catalyst increases the rate because
Lower activation energy or Ea, which allows low
energy collisions to be successful
Movie- The catalyst KI is added to H2O2, food colouring, and
dishwashing detergent. The O2 produced makes foam.
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
4.
Changing the nature of the reactant for a more reactive
chemical changes the rate because
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
4.
Changing the nature of the reactant for a more reactive
chemical changes the rate because
Lower activation energy or Ea, which allows low
energy collisions to be more effective
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
5.
Increasing the surface area of a solid reactant increases
the rate because:
The Collision Theory can be used to explain how the rate
of a reaction can be changed.
5.
Increasing the surface area of a solid reactant increases
the rate because:
More frequent collisions
Explain each Scenario Using the Collision Theory
1.
A balloon full of H2 and O2 do not react at room
temperature.
A small spark ignites causes an explosion.
Explain each Scenario Using the Collision Theory
1.
A balloon full of H2 and O2 do not react at room
temperature.
Ea is too high for the room temperature collisions
A small spark ignites causes an explosion.
Explain each Scenario Using the Collision Theory
1.
A balloon full of H2 and O2 do not react at room
temperature.
Ea is too high for the room temperature collisions
A small spark ignites causes an explosion.
The spark provides the Ea and it explodes because it
is exothermic
Explain each Scenario Using the Collision Theory
2.
A candle does not burn at room temperature
A match causes the candle to burn.
The candle continues to burn
Explain each Scenario Using the Collision Theory
2.
A candle does not burn at room temperature
Ea is too high for the room temperature collisions
A match causes the candle to burn.
The candle continues to burn
Explain each Scenario Using the Collision Theory
2.
A candle does not burn at room temperature
Ea is too high for the room temperature collisions
A match causes the candle to burn.
The match provides the Ea
The candle continues to burn
Explain each Scenario Using the Collision Theory
2.
A candle does not burn at room temperature
Ea is too high for the room temperature collisions
A match causes the candle to burn.
The match provides the Ea
The candle continues to burn
It burns because it is exothermic
Explain each Scenario Using the Collision Theory
3.
H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) + 2H2O(l)
KI increases the reaction rate dramatically.
Explain each Scenario Using the Collision Theory
3.
H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) + 2H2O(l)
KI increases the reaction rate dramatically.
Explain each Scenario Using the Collision Theory
3.
H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) + 2H2O(l)
KI increases the reaction rate dramatically.
KI is a catalyst as it is not a reactant and it speeds up
the rate.
Explain each Scenario Using the Collision Theory
3.
H2O2 decomposes very slowly at room temperature.
2H2O2(aq) → O2(g) + 2H2O(l)
KI increases the reaction rate dramatically.
KI is a catalyst as it is not a reactant and it speeds up
the rate.
Lowers the activation energy or Ea, which allows low
energy collisions to be more effective
Describe and Graph the Relationship between the
Following
Ea and the rate
Rate
Ea
Describe and Graph the Relationship between the
Following
Ea and the rate
Decreasing the Ea increases the rate- inverse.
Rate
Ea
Describe and Graph the Relationship between the
Following
Ea and the rate
Decreasing the Ea increases the rate- inverse.
Rate
Ea
Describe and Graph the Relationship between the
Following
Temperature and the rate
Rate
Temp
Describe and Graph the Relationship between the
Following
Temperature and the rate
Increasing the temperature increases the rate- direct.
Rate
Temp
Describe and Graph the Relationship between the
Following
Temperature and the rate
Increasing the temperature increases the rate- direct.
Rate
Temp
Describe and Graph the Relationship between the
Following
Concentration and the rate
Rate
Conc
Describe and Graph the Relationship between the
Following
Concentration and the rate
Increasing the concentration increases the rate- direct.
Rate
Conc
Describe and Graph the Relationship between the
Following
Concentration and the rate
Increasing the concentration increases the rate- direct.
Rate
Conc
Describe and Graph the Relationship between the
Following
Ea and the temperature
Temp
Ea
Describe and Graph the Relationship between the
Following
Ea and the temperature
The only way to change the Ea is by adding a catalyst!
No relationship!
Temp
Ea
Describe and Graph the Relationship between the
Following
Ea and the temperature
The only way to change the Ea is by adding a catalyst!
No relationship!
Temp
Ea